Add support for XEP-0191 (Blocking command)

Fixes #791

Squash of commits:
534f25d7dae3ce6852243e28fdd0a69ac01e9463
808fdf5147f27a912a60bee39aa4bf1ddd4f43b4
1eaf8a8330710ad35ba7c368e04f909af623ae4c
31585242c2359efdcd0eeddb9745077f54dbc9eb
2e69bd0bd0286ed1e98a42f4c3421ba4d8cf524b
e904fb5015bf3a1904ab941a1957edf3b1e7abd2
eebbadf3b3816bbf8fcccb763e419fed252d266f
7c5b87724ce494e5a6e8026557ed50a8fd9f23e8
b0eaaf446937794fe19cbdb4f8309c3ff83d4e42
8c652f9e8bb3512958d9ad8c6f1326505f2d98c8
ad0ea1ad948ff6f8fde7b0b10f5163dc8852032f
f5d49897e0dba691ef53a0eddb9ed34d129ad442
a08fa64c505bd895b7c626cfad182380373be20b
de67079113e08394a276048c31f6b21baa300829
9069f342173ba30c2b20c67529c7ff497a6a257d
0169fa79d161ee898c4b6762e207087682a952d8
8585a5bd75a5d56927fed8317729bd15fffe4dcc
0053528a078369e0b65dcf71bda251072a1299c7
e901a9c3554bd7cca193e92919b463991eadfea7
c5c78257434813c69ab9b7558bcc8f7cbe858433
e905af348d46d77bc46b5f7211527684acc02fab
13a0f9a10c7892b0f90f5fabd2f2615701b0fd66
2cfba1e24b0139839e4453b92be7e20634d150cf
58e074fb5bb44b05a8104250fccd7c024c808c1a
0d6cf98fc8eab212d798ac79b336f9b70a14f06d
e23620f56b85bcab9f3b5d9ce1c01524cd9674dc
d72cd2fcc8d54176c3ff53411a69b9bb4642eff3
195143dff8836623a37094a6b8fa6aa01ef31580
5f5f3caf3a1e480a99d27ee5c34ba516419c52e4
1dee3d5861c9f9c710da4cbda3688d94c622ca93
23949b8aa32c78b27bab49bb3c4f3ff588925ce1
9bf97f8ae522796e0dacb7f6fe7a7f90f86a93a1

44 files changed, 1485 insertions, 904 deletions

diff --git a/README.md b/README.md
index 2181aa96..66213e46 100644
--- a/README.md
+++ b/README.md
@@ -50,9 +50,11 @@ run your own XMPP server for you and your friends. These XEP's are:
 * XEP-0313: Message Archive Management synchronize message history with the
   server. Catch up with messages that were sent while Conversations was
   offline.
-* XEP-0352: Client State Indication let the server know whether or not
+* XEP-0352: Client State Indication lets the server know whether or not
   Conversations is in the background. Allows the server to save bandwidth by
   withholding unimportant packages.
+* XEP-0191: Blocking command lets you blacklist spammers or block contacts
+  without removing them from your roster.
 
 ## Team
 
diff --git a/docs/XEPs.md b/docs/XEPs.md
index 980c1c65..35c7de45 100644
--- a/docs/XEPs.md
+++ b/docs/XEPs.md
@@ -16,3 +16,4 @@
 * XEP-0313: Message Archive Management
 * XEP-0333: Chat Markers
 * XEP-0352: Client State Indication
+* XEP-0191: Blocking command
diff --git a/src/main/AndroidManifest.xml b/src/main/AndroidManifest.xml
index 8fdfa85b..5662e626 100644
--- a/src/main/AndroidManifest.xml
+++ b/src/main/AndroidManifest.xml
@@ -77,6 +77,9 @@
             android:name=".ui.ChooseContactActivity"
             android:label="@string/title_activity_choose_contact" />
         <activity
+            android:name=".ui.BlocklistActivity"
+            android:label="@string/title_activity_block_list" />
+        <activity
             android:name=".ui.ManageAccountActivity"
             android:configChanges="orientation|screenSize"
             android:label="@string/title_activity_manage_accounts" />
diff --git a/src/main/java/eu/siacs/conversations/entities/Account.java b/src/main/java/eu/siacs/conversations/entities/Account.java
index d9001017..d42974c6 100644
--- a/src/main/java/eu/siacs/conversations/entities/Account.java
+++ b/src/main/java/eu/siacs/conversations/entities/Account.java
@@ -11,8 +11,10 @@ import org.json.JSONException;
 import org.json.JSONObject;
 
 import java.security.interfaces.DSAPublicKey;
+import java.util.Collection;
 import java.util.List;
 import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.CopyOnWriteArraySet;
 
 import eu.siacs.conversations.Config;
 import eu.siacs.conversations.R;
@@ -56,7 +58,7 @@ public class Account extends AbstractEntity {
 		SECURITY_ERROR(true),
 		INCOMPATIBLE_SERVER(true);
 
-		private boolean isError;
+		private final boolean isError;
 
 		public boolean isError() {
 			return this.isError;
@@ -120,6 +122,7 @@ public class Account extends AbstractEntity {
 	private String otrFingerprint;
 	private final Roster roster = new Roster(this);
 	private List<Bookmark> bookmarks = new CopyOnWriteArrayList<>();
+	private final Collection<Jid> blocklist = new CopyOnWriteArraySet<>();
 
 	public Account() {
 		this.uuid = "0";
@@ -279,7 +282,7 @@ public class Account extends AbstractEntity {
 		return values;
 	}
 
-	public void initOtrEngine(XmppConnectionService context) {
+	public void initOtrEngine(final XmppConnectionService context) {
 		this.otrEngine = new OtrEngine(context, this);
 	}
 
@@ -291,7 +294,7 @@ public class Account extends AbstractEntity {
 		return this.xmppConnection;
 	}
 
-	public void setXmppConnection(XmppConnection connection) {
+	public void setXmppConnection(final XmppConnection connection) {
 		this.xmppConnection = connection;
 	}
 
@@ -323,7 +326,7 @@ public class Account extends AbstractEntity {
 		}
 	}
 
-	public void setRosterVersion(String version) {
+	public void setRosterVersion(final String version) {
 		this.rosterVersion = version;
 	}
 
@@ -351,7 +354,7 @@ public class Account extends AbstractEntity {
 		return this.bookmarks;
 	}
 
-	public void setBookmarks(List<Bookmark> bookmarks) {
+	public void setBookmarks(final List<Bookmark> bookmarks) {
 		this.bookmarks = bookmarks;
 	}
 
@@ -399,4 +402,21 @@ public class Account extends AbstractEntity {
 			return "xmpp:" + this.getJid().toBareJid().toString();
 		}
 	}
+
+	public boolean isBlocked(final ListItem contact) {
+		final Jid jid = contact.getJid();
+		return jid != null && (blocklist.contains(jid.toBareJid()) || blocklist.contains(jid.toDomainJid()));
+	}
+
+	public boolean isBlocked(final Jid jid) {
+		return jid != null && blocklist.contains(jid.toBareJid());
+	}
+
+	public Collection<Jid> getBlocklist() {
+		return this.blocklist;
+	}
+
+	public void clearBlocklist() {
+		getBlocklist().clear();
+	}
 }
diff --git a/src/main/java/eu/siacs/conversations/entities/Blockable.java b/src/main/java/eu/siacs/conversations/entities/Blockable.java
new file mode 100644
index 00000000..dbcd55c4
--- /dev/null
+++ b/src/main/java/eu/siacs/conversations/entities/Blockable.java
@@ -0,0 +1,11 @@
+package eu.siacs.conversations.entities;
+
+import eu.siacs.conversations.xmpp.jid.Jid;
+
+public interface Blockable {
+	public boolean isBlocked();
+	public boolean isDomainBlocked();
+	public Jid getBlockedJid();
+	public Jid getJid();
+	public Account getAccount();
+}
diff --git a/src/main/java/eu/siacs/conversations/entities/Bookmark.java b/src/main/java/eu/siacs/conversations/entities/Bookmark.java
index 20905648..f81f1a87 100644
--- a/src/main/java/eu/siacs/conversations/entities/Bookmark.java
+++ b/src/main/java/eu/siacs/conversations/entities/Bookmark.java
@@ -6,7 +6,6 @@ import java.util.Locale;
 
 import eu.siacs.conversations.utils.UIHelper;
 import eu.siacs.conversations.xml.Element;
-import eu.siacs.conversations.xmpp.jid.InvalidJidException;
 import eu.siacs.conversations.xmpp.jid.Jid;
 
 public class Bookmark extends Element implements ListItem {
diff --git a/src/main/java/eu/siacs/conversations/entities/Contact.java b/src/main/java/eu/siacs/conversations/entities/Contact.java
index 0820504f..af26981e 100644
--- a/src/main/java/eu/siacs/conversations/entities/Contact.java
+++ b/src/main/java/eu/siacs/conversations/entities/Contact.java
@@ -16,7 +16,7 @@ import eu.siacs.conversations.xml.Element;
 import eu.siacs.conversations.xmpp.jid.InvalidJidException;
 import eu.siacs.conversations.xmpp.jid.Jid;
 
-public class Contact implements ListItem {
+public class Contact implements ListItem, Blockable {
 	public static final String TABLENAME = "contacts";
 
 	public static final String SYSTEMNAME = "systemname";
@@ -47,8 +47,8 @@ public class Contact implements ListItem {
 	protected Account account;
 
 	public Contact(final String account, final String systemName, final String serverName,
-				   final Jid jid, final int subscription, final String photoUri,
-				   final String systemAccount, final String keys, final String avatar, final Lastseen lastseen, final String groups) {
+			final Jid jid, final int subscription, final String photoUri,
+			final String systemAccount, final String keys, final String avatar, final Lastseen lastseen, final String groups) {
 		this.accountUuid = account;
 		this.systemName = systemName;
 		this.serverName = serverName;
@@ -122,11 +122,10 @@ public class Contact implements ListItem {
 
 	@Override
 	public List<Tag> getTags() {
-		ArrayList<Tag> tags = new ArrayList<Tag>();
-		for (String group : getGroups()) {
+		final ArrayList<Tag> tags = new ArrayList<>();
+		for (final String group : getGroups()) {
 			tags.add(new Tag(group, UIHelper.getColorForName(group)));
 		}
-		int status = getMostAvailableStatus();
 		switch (getMostAvailableStatus()) {
 			case Presences.CHAT:
 			case Presences.ONLINE:
@@ -142,6 +141,9 @@ public class Contact implements ListItem {
 				tags.add(new Tag("dnd", 0xffe51c23));
 				break;
 		}
+		if (isBlocked()) {
+			tags.add(new Tag("blocked", 0xff2e2f3b));
+		}
 		return tags;
 	}
 
@@ -176,7 +178,7 @@ public class Contact implements ListItem {
 	}
 
 	public ContentValues getContentValues() {
-		ContentValues values = new ContentValues();
+		final ContentValues values = new ContentValues();
 		values.put(ACCOUNT, accountUuid);
 		values.put(SYSTEMNAME, systemName);
 		values.put(SERVERNAME, serverName);
@@ -213,11 +215,11 @@ public class Contact implements ListItem {
 		this.presences = pres;
 	}
 
-	public void updatePresence(String resource, int status) {
+	public void updatePresence(final String resource, final int status) {
 		this.presences.updatePresence(resource, status);
 	}
 
-	public void removePresence(String resource) {
+	public void removePresence(final String resource) {
 		this.presences.removePresence(resource);
 	}
 
@@ -337,8 +339,8 @@ public class Contact implements ListItem {
 
 	public boolean showInRoster() {
 		return (this.getOption(Contact.Options.IN_ROSTER) && (!this
-				.getOption(Contact.Options.DIRTY_DELETE)))
-				|| (this.getOption(Contact.Options.DIRTY_PUSH));
+					.getOption(Contact.Options.DIRTY_DELETE)))
+			|| (this.getOption(Contact.Options.DIRTY_PUSH));
 	}
 
 	public void parseSubscriptionFromElement(Element item) {
@@ -428,7 +430,7 @@ public class Contact implements ListItem {
 			if (this.keys.has("otr_fingerprints")) {
 				JSONArray newPrints = new JSONArray();
 				JSONArray oldPrints = this.keys
-						.getJSONArray("otr_fingerprints");
+					.getJSONArray("otr_fingerprints");
 				for (int i = 0; i < oldPrints.length(); ++i) {
 					if (!oldPrints.getString(i).equals(fingerprint)) {
 						newPrints.put(oldPrints.getString(i));
@@ -457,22 +459,40 @@ public class Contact implements ListItem {
 		}
 	}
 
+	@Override
+	public boolean isBlocked() {
+		return getAccount().isBlocked(this);
+	}
+
+	@Override
+	public boolean isDomainBlocked() {
+		return getAccount().isBlocked(this.getJid().toDomainJid());
+	}
+
+	@Override
+	public Jid getBlockedJid() {
+		if (isDomainBlocked()) {
+			return getJid().toDomainJid();
+		} else {
+			return getJid();
+		}
+	}
+
 	public static class Lastseen {
 		public long time;
 		public String presence;
 
 		public Lastseen() {
-			time = 0;
-			presence = null;
+			this(null, 0);
 		}
 
 		public Lastseen(final String presence, final long time) {
-			this.time = time;
 			this.presence = presence;
+			this.time = time;
 		}
 	}
 
-	public class Options {
+	public final class Options {
 		public static final int TO = 0;
 		public static final int FROM = 1;
 		public static final int ASKING = 2;
diff --git a/src/main/java/eu/siacs/conversations/entities/Conversation.java b/src/main/java/eu/siacs/conversations/entities/Conversation.java
index e8482a96..22ddd307 100644
--- a/src/main/java/eu/siacs/conversations/entities/Conversation.java
+++ b/src/main/java/eu/siacs/conversations/entities/Conversation.java
@@ -3,7 +3,6 @@ package eu.siacs.conversations.entities;
 import android.content.ContentValues;
 import android.database.Cursor;
 import android.os.SystemClock;
-import android.util.Log;
 
 import net.java.otr4j.OtrException;
 import net.java.otr4j.crypto.OtrCryptoEngineImpl;
@@ -25,7 +24,7 @@ import eu.siacs.conversations.Config;
 import eu.siacs.conversations.xmpp.jid.InvalidJidException;
 import eu.siacs.conversations.xmpp.jid.Jid;
 
-public class Conversation extends AbstractEntity {
+public class Conversation extends AbstractEntity implements Blockable {
 	public static final String TABLENAME = "conversations";
 
 	public static final int STATUS_AVAILABLE = 0;
@@ -105,7 +104,7 @@ public class Conversation extends AbstractEntity {
 				if ((message.getType() == Message.TYPE_IMAGE || message.getType() == Message.TYPE_FILE)
 						&& message.getEncryption() != Message.ENCRYPTION_PGP) {
 					onMessageFound.onMessageFound(message);
-				}
+						}
 			}
 		}
 	}
@@ -117,7 +116,7 @@ public class Conversation extends AbstractEntity {
 						&& message.getEncryption() != Message.ENCRYPTION_PGP
 						&& message.getUuid().equals(uuid)) {
 					return message;
-				}
+						}
 			}
 		}
 		return null;
@@ -145,7 +144,7 @@ public class Conversation extends AbstractEntity {
 				if ((message.getStatus() == Message.STATUS_UNSEND || message.getStatus() == Message.STATUS_WAITING)
 						&& (message.getEncryption() == Message.ENCRYPTION_OTR)) {
 					onMessageFound.onMessageFound(message);
-				}
+						}
 			}
 		}
 	}
@@ -156,7 +155,7 @@ public class Conversation extends AbstractEntity {
 				if (message.getType() != Message.TYPE_IMAGE
 						&& message.getStatus() == Message.STATUS_UNSEND) {
 					onMessageFound.onMessageFound(message);
-				}
+						}
 			}
 		}
 	}
@@ -166,21 +165,37 @@ public class Conversation extends AbstractEntity {
 			for (Message message : this.messages) {
 				if (uuid.equals(message.getUuid())
 						|| (message.getStatus() >= Message.STATUS_SEND && uuid
-						.equals(message.getRemoteMsgId()))) {
+							.equals(message.getRemoteMsgId()))) {
 					return message;
-				}
+							}
 			}
 		}
 		return null;
 	}
 
-	public void populateWithMessages(List<Message> messages) {
+	public void populateWithMessages(final List<Message> messages) {
 		synchronized (this.messages) {
 			messages.clear();
 			messages.addAll(this.messages);
 		}
 	}
 
+	@Override
+	public boolean isBlocked() {
+		return getContact().isBlocked();
+	}
+
+	@Override
+	public boolean isDomainBlocked() {
+		return getContact().isDomainBlocked();
+	}
+
+	@Override
+	public Jid getBlockedJid() {
+		return getContact().getBlockedJid();
+	}
+
+
 	public interface OnMessageFound {
 		public void onMessageFound(final Message message);
 	}
@@ -212,8 +227,8 @@ public class Conversation extends AbstractEntity {
 	}
 
 	public boolean isRead() {
-        return (this.messages == null) || (this.messages.size() == 0) || this.messages.get(this.messages.size() - 1).isRead();
-    }
+		return (this.messages == null) || (this.messages.size() == 0) || this.messages.get(this.messages.size() - 1).isRead();
+	}
 
 	public void markRead() {
 		if (this.messages == null) {
@@ -239,7 +254,7 @@ public class Conversation extends AbstractEntity {
 				} else {
 					return this.messages.get(i);
 				}
-			}
+					}
 		}
 		return null;
 	}
@@ -267,7 +282,7 @@ public class Conversation extends AbstractEntity {
 				if (generatedName != null) {
 					return generatedName;
 				} else {
-					return getContactJid().getLocalpart();
+					return getJid().getLocalpart();
 				}
 			}
 		} else {
@@ -287,11 +302,12 @@ public class Conversation extends AbstractEntity {
 		return this.account.getRoster().getContact(this.contactJid);
 	}
 
-	public void setAccount(Account account) {
+	public void setAccount(final Account account) {
 		this.account = account;
 	}
 
-	public Jid getContactJid() {
+	@Override
+	public Jid getJid() {
 		return this.contactJid;
 	}
 
@@ -318,14 +334,14 @@ public class Conversation extends AbstractEntity {
 	}
 
 	public static Conversation fromCursor(Cursor cursor) {
-        Jid jid;
-        try {
-            jid = Jid.fromString(cursor.getString(cursor.getColumnIndex(CONTACTJID)));
-        } catch (final InvalidJidException e) {
-            // Borked DB..
-            jid = null;
-        }
-        return new Conversation(cursor.getString(cursor.getColumnIndex(UUID)),
+		Jid jid;
+		try {
+			jid = Jid.fromString(cursor.getString(cursor.getColumnIndex(CONTACTJID)));
+		} catch (final InvalidJidException e) {
+			// Borked DB..
+			jid = null;
+		}
+		return new Conversation(cursor.getString(cursor.getColumnIndex(UUID)),
 				cursor.getString(cursor.getColumnIndex(NAME)),
 				cursor.getString(cursor.getColumnIndex(CONTACT)),
 				cursor.getString(cursor.getColumnIndex(ACCOUNT)),
@@ -352,9 +368,9 @@ public class Conversation extends AbstractEntity {
 		if (this.otrSession != null) {
 			return this.otrSession;
 		} else {
-            final SessionID sessionId = new SessionID(this.getContactJid().toBareJid().toString(),
-                    presence,
-                    "xmpp");
+			final SessionID sessionId = new SessionID(this.getJid().toBareJid().toString(),
+					presence,
+					"xmpp");
 			this.otrSession = new SessionImpl(sessionId, getAccount().getOtrEngine());
 			try {
 				if (sendStart) {
@@ -393,7 +409,7 @@ public class Conversation extends AbstractEntity {
 			} catch (OtrException e) {
 				this.resetOtrSession();
 			}
-		}
+				}
 	}
 
 	public boolean endOtrIfNeeded() {
@@ -427,7 +443,7 @@ public class Conversation extends AbstractEntity {
 					return "";
 				}
 				DSAPublicKey remotePubKey = (DSAPublicKey) getOtrSession()
-						.getRemotePublicKey();
+					.getRemotePublicKey();
 				StringBuilder builder = new StringBuilder(
 						new OtrCryptoEngineImpl().getFingerprint(remotePubKey));
 				builder.insert(8, " ");
diff --git a/src/main/java/eu/siacs/conversations/entities/ListItem.java b/src/main/java/eu/siacs/conversations/entities/ListItem.java
index db9fbc37..efc1c2b9 100644
--- a/src/main/java/eu/siacs/conversations/entities/ListItem.java
+++ b/src/main/java/eu/siacs/conversations/entities/ListItem.java
@@ -12,10 +12,10 @@ public interface ListItem extends Comparable<ListItem> {
 	public List<Tag> getTags();
 
 	public final class Tag {
-		private String name;
-		private int color;
+		private final String name;
+		private final int color;
 
-		public Tag(String name, int color) {
+		public Tag(final String name, final int color) {
 			this.name = name;
 			this.color = color;
 		}
@@ -28,4 +28,6 @@ public interface ListItem extends Comparable<ListItem> {
 			return this.name;
 		}
 	}
+
+	public boolean match(final String needle);
 }
diff --git a/src/main/java/eu/siacs/conversations/entities/Message.java b/src/main/java/eu/siacs/conversations/entities/Message.java
index 5b937138..38e88fa4 100644
--- a/src/main/java/eu/siacs/conversations/entities/Message.java
+++ b/src/main/java/eu/siacs/conversations/entities/Message.java
@@ -77,7 +77,7 @@ public class Message extends AbstractEntity {
 	public Message(Conversation conversation, String body, int encryption, int status) {
 		this(java.util.UUID.randomUUID().toString(),
 				conversation.getUuid(),
-				conversation.getContactJid() == null ? null : conversation.getContactJid().toBareJid(),
+				conversation.getJid() == null ? null : conversation.getJid().toBareJid(),
 				null,
 				body,
 				System.currentTimeMillis(),
@@ -91,9 +91,9 @@ public class Message extends AbstractEntity {
 	}
 
 	private Message(final String uuid, final String conversationUUid, final Jid counterpart,
-				   final Jid trueCounterpart, final String body, final long timeSent,
-				   final int encryption, final int status, final int type, final String remoteMsgId,
-				   final String relativeFilePath, final String serverMsgId) {
+			final Jid trueCounterpart, final String body, final long timeSent,
+			final int encryption, final int status, final int type, final String remoteMsgId,
+			final String relativeFilePath, final String serverMsgId) {
 		this.uuid = uuid;
 		this.conversationUuid = conversationUUid;
 		this.counterpart = counterpart;
@@ -206,7 +206,7 @@ public class Message extends AbstractEntity {
 				return null;
 			} else {
 				return this.conversation.getAccount().getRoster()
-						.getContactFromRoster(this.trueCounterpart);
+					.getContactFromRoster(this.trueCounterpart);
 			}
 		}
 	}
@@ -312,10 +312,10 @@ public class Message extends AbstractEntity {
 			return this.serverMsgId.equals(message.getServerMsgId());
 		} else {
 			return this.body != null
-					&& this.counterpart != null
-					&& ((this.remoteMsgId != null && this.remoteMsgId.equals(message.getRemoteMsgId()))
-					|| this.uuid.equals(message.getRemoteMsgId())) && this.body.equals(message.getBody())
-					&& this.counterpart.equals(message.getCounterpart());
+				&& this.counterpart != null
+				&& ((this.remoteMsgId != null && this.remoteMsgId.equals(message.getRemoteMsgId()))
+						|| this.uuid.equals(message.getRemoteMsgId())) && this.body.equals(message.getBody())
+				&& this.counterpart.equals(message.getCounterpart());
 		}
 	}
 
@@ -388,7 +388,7 @@ public class Message extends AbstractEntity {
 			if (!url.getProtocol().equalsIgnoreCase("http")
 					&& !url.getProtocol().equalsIgnoreCase("https")) {
 				return false;
-			}
+					}
 			if (url.getPath() == null) {
 				return false;
 			}
@@ -402,14 +402,14 @@ public class Message extends AbstractEntity {
 			String[] extensionParts = filename.split("\\.");
 			if (extensionParts.length == 2
 					&& Arrays.asList(Downloadable.VALID_IMAGE_EXTENSIONS).contains(
-					extensionParts[extensionParts.length - 1])) {
+						extensionParts[extensionParts.length - 1])) {
 				return true;
 			} else if (extensionParts.length == 3
 					&& Arrays
 					.asList(Downloadable.VALID_CRYPTO_EXTENSIONS)
 					.contains(extensionParts[extensionParts.length - 1])
 					&& Arrays.asList(Downloadable.VALID_IMAGE_EXTENSIONS).contains(
-					extensionParts[extensionParts.length - 2])) {
+						extensionParts[extensionParts.length - 2])) {
 				return true;
 			} else {
 				return false;
diff --git a/src/main/java/eu/siacs/conversations/entities/MucOptions.java b/src/main/java/eu/siacs/conversations/entities/MucOptions.java
index c8706fc9..97a63532 100644
--- a/src/main/java/eu/siacs/conversations/entities/MucOptions.java
+++ b/src/main/java/eu/siacs/conversations/entities/MucOptions.java
@@ -80,20 +80,20 @@ public class MucOptions {
 
 		public void setRole(String role) {
 			role = role.toLowerCase();
-            switch (role) {
-                case "moderator":
-                    this.role = ROLE_MODERATOR;
-                    break;
-                case "participant":
-                    this.role = ROLE_PARTICIPANT;
-                    break;
-                case "visitor":
-                    this.role = ROLE_VISITOR;
-                    break;
-                default:
-                    this.role = ROLE_NONE;
-                    break;
-            }
+			switch (role) {
+				case "moderator":
+					this.role = ROLE_MODERATOR;
+					break;
+				case "participant":
+					this.role = ROLE_PARTICIPANT;
+					break;
+				case "visitor":
+					this.role = ROLE_VISITOR;
+					break;
+				default:
+					this.role = ROLE_NONE;
+					break;
+			}
 		}
 
 		public int getAffiliation() {
@@ -164,7 +164,7 @@ public class MucOptions {
 	}
 
 	public void processPacket(PresencePacket packet, PgpEngine pgp) {
-        final Jid from = packet.getFrom();
+		final Jid from = packet.getFrom();
 		if (!from.isBareJid()) {
 			final String name = from.getResourcepart();
 			final String type = packet.getAttribute("type");
@@ -179,7 +179,7 @@ public class MucOptions {
 						user.setAffiliation(item.getAttribute("affiliation"));
 						user.setRole(item.getAttribute("role"));
 						user.setJid(item.getAttributeAsJid("jid"));
-						if (codes.contains(STATUS_CODE_SELF_PRESENCE) || packet.getFrom().equals(this.conversation.getContactJid())) {
+						if (codes.contains(STATUS_CODE_SELF_PRESENCE) || packet.getFrom().equals(this.conversation.getJid())) {
 							this.isOnline = true;
 							this.error = ERROR_NO_ERROR;
 							self = user;
@@ -204,14 +204,14 @@ public class MucOptions {
 									msg = "";
 								}
 								user.setPgpKeyId(pgp.fetchKeyId(account, msg,
-										signed.getContent()));
+											signed.getContent()));
 							}
 						}
 					}
 				}
 			} else if (type.equals("unavailable")) {
 				if (codes.contains(STATUS_CODE_SELF_PRESENCE) ||
-						packet.getFrom().equals(this.conversation.getContactJid())) {
+						packet.getFrom().equals(this.conversation.getJid())) {
 					if (codes.contains(STATUS_CODE_CHANGED_NICK)) {
 						this.mNickChangingInProgress = true;
 					} else if (codes.contains(STATUS_CODE_KICKED)) {
@@ -282,8 +282,8 @@ public class MucOptions {
 				&& conversation.getBookmark().getNick() != null
 				&& !conversation.getBookmark().getNick().isEmpty()) {
 			return conversation.getBookmark().getNick();
-		} else if (!conversation.getContactJid().isBareJid()) {
-			return conversation.getContactJid().getResourcepart();
+		} else if (!conversation.getJid().isBareJid()) {
+			return conversation.getJid().getResourcepart();
 		} else {
 			return account.getUsername();
 		}
@@ -334,14 +334,14 @@ public class MucOptions {
 	public String createNameFromParticipants() {
 		if (users.size() >= 2) {
 			List<String> names = new ArrayList<String>();
-				for (User user : users) {
-					Contact contact = user.getContact();
-					if (contact != null && !contact.getDisplayName().isEmpty()) {
-						names.add(contact.getDisplayName().split("\\s+")[0]);
-					} else {
-						names.add(user.getName());
-					}
+			for (User user : users) {
+				Contact contact = user.getContact();
+				if (contact != null && !contact.getDisplayName().isEmpty()) {
+					names.add(contact.getDisplayName().split("\\s+")[0]);
+				} else {
+					names.add(user.getName());
 				}
+			}
 			StringBuilder builder = new StringBuilder();
 			for (int i = 0; i < names.size(); ++i) {
 				builder.append(names.get(i));
@@ -388,12 +388,12 @@ public class MucOptions {
 	}
 
 	public Jid createJoinJid(String nick) {
-        try {
-            return Jid.fromString(this.conversation.getContactJid().toBareJid().toString() + "/"+nick);
-        } catch (final InvalidJidException e) {
-            return null;
-        }
-    }
+		try {
+			return Jid.fromString(this.conversation.getJid().toBareJid().toString() + "/"+nick);
+		} catch (final InvalidJidException e) {
+			return null;
+		}
+	}
 
 	public Jid getTrueCounterpart(String counterpart) {
 		for (User user : this.getUsers()) {
diff --git a/src/main/java/eu/siacs/conversations/entities/Roster.java b/src/main/java/eu/siacs/conversations/entities/Roster.java
index 12a89cec..1a81a419 100644
--- a/src/main/java/eu/siacs/conversations/entities/Roster.java
+++ b/src/main/java/eu/siacs/conversations/entities/Roster.java
@@ -7,7 +7,7 @@ import java.util.concurrent.ConcurrentHashMap;
 import eu.siacs.conversations.xmpp.jid.Jid;
 
 public class Roster {
-	Account account;
+	final Account account;
 	final ConcurrentHashMap<String, Contact> contacts = new ConcurrentHashMap<>();
 	private String version = null;
 
@@ -19,7 +19,7 @@ public class Roster {
 		if (jid == null) {
 			return null;
 		}
-		Contact contact = contacts.get(jid.toBareJid().toString());
+		final Contact contact = contacts.get(jid.toBareJid().toString());
 		if (contact != null && contact.showInRoster()) {
 			return contact;
 		} else {
@@ -32,7 +32,7 @@ public class Roster {
 		if (contacts.containsKey(bareJid.toString())) {
 			return contacts.get(bareJid.toString());
 		} else {
-			Contact contact = new Contact(bareJid);
+			final Contact contact = new Contact(bareJid);
 			contact.setAccount(account);
 			contacts.put(bareJid.toString(), contact);
 			return contact;
@@ -46,13 +46,13 @@ public class Roster {
 	}
 
 	public void markAllAsNotInRoster() {
-		for (Contact contact : getContacts()) {
+		for (final Contact contact : getContacts()) {
 			contact.resetOption(Contact.Options.IN_ROSTER);
 		}
 	}
 
 	public void clearSystemAccounts() {
-		for (Contact contact : getContacts()) {
+		for (final Contact contact : getContacts()) {
 			contact.setPhotoUri(null);
 			contact.setSystemName(null);
 			contact.setSystemAccount(null);
diff --git a/src/main/java/eu/siacs/conversations/generator/IqGenerator.java b/src/main/java/eu/siacs/conversations/generator/IqGenerator.java
index 4819f96e..4b28e484 100644
--- a/src/main/java/eu/siacs/conversations/generator/IqGenerator.java
+++ b/src/main/java/eu/siacs/conversations/generator/IqGenerator.java
@@ -1,14 +1,12 @@
 package eu.siacs.conversations.generator;
 
-import android.util.Log;
-
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 
-import eu.siacs.conversations.Config;
 import eu.siacs.conversations.services.MessageArchiveService;
 import eu.siacs.conversations.services.XmppConnectionService;
+import eu.siacs.conversations.utils.Xmlns;
 import eu.siacs.conversations.xml.Element;
 import eu.siacs.conversations.xmpp.forms.Data;
 import eu.siacs.conversations.xmpp.jid.Jid;
@@ -17,44 +15,44 @@ import eu.siacs.conversations.xmpp.stanzas.IqPacket;
 
 public class IqGenerator extends AbstractGenerator {
 
-	public IqGenerator(XmppConnectionService service) {
+	public IqGenerator(final XmppConnectionService service) {
 		super(service);
 	}
 
-	public IqPacket discoResponse(IqPacket request) {
-		IqPacket packet = new IqPacket(IqPacket.TYPE_RESULT);
+	public IqPacket discoResponse(final IqPacket request) {
+		final IqPacket packet = new IqPacket(IqPacket.TYPE_RESULT);
 		packet.setId(request.getId());
-        packet.setTo(request.getFrom());
-		Element query = packet.addChild("query",
+		packet.setTo(request.getFrom());
+		final Element query = packet.addChild("query",
 				"http://jabber.org/protocol/disco#info");
 		query.setAttribute("node", request.query().getAttribute("node"));
-		Element identity = query.addChild("identity");
+		final Element identity = query.addChild("identity");
 		identity.setAttribute("category", "client");
 		identity.setAttribute("type", this.IDENTITY_TYPE);
 		identity.setAttribute("name", IDENTITY_NAME);
-		List<String> features = Arrays.asList(FEATURES);
+		final List<String> features = Arrays.asList(FEATURES);
 		Collections.sort(features);
-		for (String feature : features) {
+		for (final String feature : features) {
 			query.addChild("feature").setAttribute("var", feature);
 		}
 		return packet;
 	}
 
-	protected IqPacket publish(String node, Element item) {
-		IqPacket packet = new IqPacket(IqPacket.TYPE_SET);
-		Element pubsub = packet.addChild("pubsub",
+	protected IqPacket publish(final String node, final Element item) {
+		final IqPacket packet = new IqPacket(IqPacket.TYPE_SET);
+		final Element pubsub = packet.addChild("pubsub",
 				"http://jabber.org/protocol/pubsub");
-		Element publish = pubsub.addChild("publish");
+		final Element publish = pubsub.addChild("publish");
 		publish.setAttribute("node", node);
 		publish.addChild(item);
 		return packet;
 	}
 
 	protected IqPacket retrieve(String node, Element item) {
-		IqPacket packet = new IqPacket(IqPacket.TYPE_GET);
-		Element pubsub = packet.addChild("pubsub",
+		final IqPacket packet = new IqPacket(IqPacket.TYPE_GET);
+		final Element pubsub = packet.addChild("pubsub",
 				"http://jabber.org/protocol/pubsub");
-		Element items = pubsub.addChild("items");
+		final Element items = pubsub.addChild("items");
 		items.setAttribute("node", node);
 		if (item != null) {
 			items.addChild(item);
@@ -63,19 +61,19 @@ public class IqGenerator extends AbstractGenerator {
 	}
 
 	public IqPacket publishAvatar(Avatar avatar) {
-		Element item = new Element("item");
+		final Element item = new Element("item");
 		item.setAttribute("id", avatar.sha1sum);
-		Element data = item.addChild("data", "urn:xmpp:avatar:data");
+		final Element data = item.addChild("data", "urn:xmpp:avatar:data");
 		data.setContent(avatar.image);
 		return publish("urn:xmpp:avatar:data", item);
 	}
 
-	public IqPacket publishAvatarMetadata(Avatar avatar) {
-		Element item = new Element("item");
+	public IqPacket publishAvatarMetadata(final Avatar avatar) {
+		final Element item = new Element("item");
 		item.setAttribute("id", avatar.sha1sum);
-		Element metadata = item
-				.addChild("metadata", "urn:xmpp:avatar:metadata");
-		Element info = metadata.addChild("info");
+		final Element metadata = item
+			.addChild("metadata", "urn:xmpp:avatar:metadata");
+		final Element info = metadata.addChild("info");
 		info.setAttribute("bytes", avatar.size);
 		info.setAttribute("id", avatar.sha1sum);
 		info.setAttribute("height", avatar.height);
@@ -84,10 +82,10 @@ public class IqGenerator extends AbstractGenerator {
 		return publish("urn:xmpp:avatar:metadata", item);
 	}
 
-	public IqPacket retrieveAvatar(Avatar avatar) {
-		Element item = new Element("item");
+	public IqPacket retrieveAvatar(final Avatar avatar) {
+		final Element item = new Element("item");
 		item.setAttribute("id", avatar.sha1sum);
-		IqPacket packet = retrieve("urn:xmpp:avatar:data", item);
+		final IqPacket packet = retrieve("urn:xmpp:avatar:data", item);
 		packet.setTo(avatar.owner);
 		return packet;
 	}
@@ -100,11 +98,11 @@ public class IqGenerator extends AbstractGenerator {
 		return packet;
 	}
 
-	public IqPacket queryMessageArchiveManagement(MessageArchiveService.Query mam) {
+	public IqPacket queryMessageArchiveManagement(final MessageArchiveService.Query mam) {
 		final IqPacket packet = new IqPacket(IqPacket.TYPE_SET);
-		Element query = packet.query("urn:xmpp:mam:0");
+		final Element query = packet.query("urn:xmpp:mam:0");
 		query.setAttribute("queryid",mam.getQueryId());
-		Data data = new Data();
+		final Data data = new Data();
 		data.setFormType("urn:xmpp:mam:0");
 		if (mam.getWith()!=null) {
 			data.put("with", mam.getWith().toString());
@@ -119,4 +117,25 @@ public class IqGenerator extends AbstractGenerator {
 		}
 		return packet;
 	}
+
+	public IqPacket generateGetBlockList() {
+		final IqPacket iq = new IqPacket(IqPacket.TYPE_GET);
+		iq.addChild("blocklist", Xmlns.BLOCKING);
+
+		return iq;
+	}
+
+	public IqPacket generateSetBlockRequest(final Jid jid) {
+		final IqPacket iq = new IqPacket(IqPacket.TYPE_SET);
+		final Element block = iq.addChild("block", Xmlns.BLOCKING);
+		block.addChild("item").setAttribute("jid", jid.toBareJid().toString());
+		return iq;
+	}
+
+	public IqPacket generateSetUnblockRequest(final Jid jid) {
+		final IqPacket iq = new IqPacket(IqPacket.TYPE_SET);
+		final Element block = iq.addChild("unblock", Xmlns.BLOCKING);
+		block.addChild("item").setAttribute("jid", jid.toBareJid().toString());
+		return iq;
+	}
 }
diff --git a/src/main/java/eu/siacs/conversations/generator/MessageGenerator.java b/src/main/java/eu/siacs/conversations/generator/MessageGenerator.java
index ca5417e0..8e99888b 100644
--- a/src/main/java/eu/siacs/conversations/generator/MessageGenerator.java
+++ b/src/main/java/eu/siacs/conversations/generator/MessageGenerator.java
@@ -114,7 +114,7 @@ public class MessageGenerator extends AbstractGenerator {
 	private MessagePacket generateError(MessagePacket origin) {
 		MessagePacket packet = new MessagePacket();
 		packet.setId(origin.getId());
-        packet.setTo(origin.getFrom());
+		packet.setTo(origin.getFrom());
 		packet.setBody(origin.getBody());
 		packet.setType(MessagePacket.TYPE_ERROR);
 		return packet;
@@ -135,7 +135,7 @@ public class MessageGenerator extends AbstractGenerator {
 			String subject) {
 		MessagePacket packet = new MessagePacket();
 		packet.setType(MessagePacket.TYPE_GROUPCHAT);
-		packet.setTo(conversation.getContactJid().toBareJid());
+		packet.setTo(conversation.getJid().toBareJid());
 		Element subjectChild = new Element("subject");
 		subjectChild.setContent(subject);
 		packet.addChild(subjectChild);
@@ -149,13 +149,13 @@ public class MessageGenerator extends AbstractGenerator {
 		packet.setTo(contact);
 		packet.setFrom(conversation.getAccount().getJid());
 		Element x = packet.addChild("x", "jabber:x:conference");
-		x.setAttribute("jid", conversation.getContactJid().toBareJid().toString());
+		x.setAttribute("jid", conversation.getJid().toBareJid().toString());
 		return packet;
 	}
 
 	public MessagePacket invite(Conversation conversation, Jid contact) {
 		MessagePacket packet = new MessagePacket();
-		packet.setTo(conversation.getContactJid().toBareJid());
+		packet.setTo(conversation.getJid().toBareJid());
 		packet.setFrom(conversation.getAccount().getJid());
 		Element x = new Element("x");
 		x.setAttribute("xmlns", "http://jabber.org/protocol/muc#user");
@@ -170,7 +170,7 @@ public class MessageGenerator extends AbstractGenerator {
 			MessagePacket originalMessage, String namespace) {
 		MessagePacket receivedPacket = new MessagePacket();
 		receivedPacket.setType(MessagePacket.TYPE_NORMAL);
-        receivedPacket.setTo(originalMessage.getFrom());
+		receivedPacket.setTo(originalMessage.getFrom());
 		receivedPacket.setFrom(account.getJid());
 		Element received = receivedPacket.addChild("received", namespace);
 		received.setAttribute("id", originalMessage.getId());
diff --git a/src/main/java/eu/siacs/conversations/parser/AbstractParser.java b/src/main/java/eu/siacs/conversations/parser/AbstractParser.java
index 39cbff4f..8afc2ae0 100644
--- a/src/main/java/eu/siacs/conversations/parser/AbstractParser.java
+++ b/src/main/java/eu/siacs/conversations/parser/AbstractParser.java
@@ -53,10 +53,10 @@ public abstract class AbstractParser {
 
 	protected void updateLastseen(final Element packet, final Account account,
 			final boolean presenceOverwrite) {
-        Jid from = packet.getAttributeAsJid("from");
-        String presence = from == null || from.isBareJid() ? "" : from.getResourcepart();
-		Contact contact = account.getRoster().getContact(from);
-		long timestamp = getTimestamp(packet);
+		final Jid from = packet.getAttributeAsJid("from");
+		final String presence = from == null || from.isBareJid() ? "" : from.getResourcepart();
+		final Contact contact = account.getRoster().getContact(from);
+		final long timestamp = getTimestamp(packet);
 		if (timestamp >= contact.lastseen.time) {
 			contact.lastseen.time = timestamp;
 			if (!presence.isEmpty() && presenceOverwrite) {
diff --git a/src/main/java/eu/siacs/conversations/parser/IqParser.java b/src/main/java/eu/siacs/conversations/parser/IqParser.java
index b583a1a1..b77d460d 100644
--- a/src/main/java/eu/siacs/conversations/parser/IqParser.java
+++ b/src/main/java/eu/siacs/conversations/parser/IqParser.java
@@ -2,36 +2,40 @@ package eu.siacs.conversations.parser;
 
 import android.util.Log;
 
+import java.util.ArrayList;
+import java.util.Collection;
+
 import eu.siacs.conversations.Config;
 import eu.siacs.conversations.entities.Account;
 import eu.siacs.conversations.entities.Contact;
 import eu.siacs.conversations.services.XmppConnectionService;
+import eu.siacs.conversations.utils.Xmlns;
 import eu.siacs.conversations.xml.Element;
 import eu.siacs.conversations.xmpp.OnIqPacketReceived;
-import eu.siacs.conversations.xmpp.jid.InvalidJidException;
+import eu.siacs.conversations.xmpp.OnUpdateBlocklist;
 import eu.siacs.conversations.xmpp.jid.Jid;
 import eu.siacs.conversations.xmpp.stanzas.IqPacket;
 
 public class IqParser extends AbstractParser implements OnIqPacketReceived {
 
-	public IqParser(XmppConnectionService service) {
+	public IqParser(final XmppConnectionService service) {
 		super(service);
 	}
 
-	public void rosterItems(Account account, Element query) {
-		String version = query.getAttribute("ver");
+	public void rosterItems(final Account account, final Element query) {
+		final String version = query.getAttribute("ver");
 		if (version != null) {
 			account.getRoster().setVersion(version);
 		}
-		for (Element item : query.getChildren()) {
+		for (final Element item : query.getChildren()) {
 			if (item.getName().equals("item")) {
 				final Jid jid = item.getAttributeAsJid("jid");
 				if (jid == null) {
 					continue;
 				}
-				String name = item.getAttribute("name");
-				String subscription = item.getAttribute("subscription");
-				Contact contact = account.getRoster().getContact(jid);
+				final String name = item.getAttribute("name");
+				final String subscription = item.getAttribute("subscription");
+				final Contact contact = account.getRoster().getContact(jid);
 				if (!contact.getOption(Contact.Options.DIRTY_PUSH)) {
 					contact.setServerName(name);
 					contact.parseGroupsFromElement(item);
@@ -54,13 +58,13 @@ public class IqParser extends AbstractParser implements OnIqPacketReceived {
 		mXmppConnectionService.updateRosterUi();
 	}
 
-	public String avatarData(IqPacket packet) {
-		Element pubsub = packet.findChild("pubsub",
+	public String avatarData(final IqPacket packet) {
+		final Element pubsub = packet.findChild("pubsub",
 				"http://jabber.org/protocol/pubsub");
 		if (pubsub == null) {
 			return null;
 		}
-		Element items = pubsub.findChild("items");
+		final Element items = pubsub.findChild("items");
 		if (items == null) {
 			return null;
 		}
@@ -68,13 +72,76 @@ public class IqParser extends AbstractParser implements OnIqPacketReceived {
 	}
 
 	@Override
-	public void onIqPacketReceived(Account account, IqPacket packet) {
+	public void onIqPacketReceived(final Account account, final IqPacket packet) {
 		if (packet.hasChild("query", "jabber:iq:roster")) {
 			final Jid from = packet.getFrom();
 			if ((from == null) || (from.equals(account.getJid().toBareJid()))) {
-				Element query = packet.findChild("query");
+				final Element query = packet.findChild("query");
 				this.rosterItems(account, query);
 			}
+		}  else if (packet.hasChild("block", Xmlns.BLOCKING) || packet.hasChild("blocklist", Xmlns.BLOCKING)) {
+			// Only accept block list changes from the server.
+			// The server should probably prevent other people from faking a blocklist push,
+			// but just in case let's prevent it client side as well.
+			final Jid from = packet.getFrom();
+			if (from == null || from.equals(account.getServer()) || from.equals(account.getJid().toBareJid())) {
+				Log.d(Config.LOGTAG, "Received blocklist update from server");
+				final Element blocklist = packet.findChild("blocklist", Xmlns.BLOCKING);
+				final Element block = packet.findChild("block", Xmlns.BLOCKING);
+				final Collection<Element> items = blocklist != null ? blocklist.getChildren() :
+					(block != null ? block.getChildren() : null);
+				// If this is a response to a blocklist query, clear the block list and replace with the new one.
+				// Otherwise, just update the existing blocklist.
+				if (packet.getType() == IqPacket.TYPE_RESULT) {
+					account.clearBlocklist();
+				}
+				if (items != null) {
+					final Collection<Jid> jids = new ArrayList<>(items.size());
+					// Create a collection of Jids from the packet
+					for (final Element item : items) {
+						if (item.getName().equals("item")) {
+							final Jid jid = item.getAttributeAsJid("jid");
+							if (jid != null) {
+								jids.add(jid);
+							}
+						}
+					}
+					account.getBlocklist().addAll(jids);
+				}
+				// Update the UI
+				mXmppConnectionService.updateBlocklistUi(OnUpdateBlocklist.Status.BLOCKED);
+			} else {
+				Log.d(Config.LOGTAG, "Received blocklist update from invalid jid: " + from.toString());
+			}
+		} else if (packet.hasChild("unblock", Xmlns.BLOCKING)) {
+			final Jid from = packet.getFrom();
+			if ((from == null || from.equals(account.getServer()) || from.equals(account.getJid().toBareJid())) &&
+					packet.getType() == IqPacket.TYPE_SET) {
+				Log.d(Config.LOGTAG, "Received unblock update from server");
+				final Collection<Element> items = packet.getChildren().get(0).getChildren();
+				if (items.size() == 0) {
+					// No children to unblock == unblock all
+					account.getBlocklist().clear();
+				} else {
+					final Collection<Jid> jids = new ArrayList<>(items.size());
+					for (final Element item : items) {
+						if (item.getName().equals("item")) {
+							final Jid jid = item.getAttributeAsJid("jid");
+							if (jid != null) {
+								jids.add(jid);
+							}
+						}
+					}
+					account.getBlocklist().removeAll(jids);
+					mXmppConnectionService.updateBlocklistUi(OnUpdateBlocklist.Status.UNBLOCKED);
+				}
+			} else {
+				if (packet.getType() == IqPacket.TYPE_SET) {
+					Log.d(Config.LOGTAG, "Received unblock update from invalid jid " + from.toString());
+				} else {
+					Log.d(Config.LOGTAG, "Received unblock update with invalid type " + packet.getType());
+				}
+			}
 		} else {
 			if (packet.getFrom() == null) {
 				Log.d(Config.LOGTAG, account.getJid().toBareJid().toString() + ": received iq with invalid from "+packet.toString());
@@ -82,24 +149,24 @@ public class IqParser extends AbstractParser implements OnIqPacketReceived {
 			} else if (packet.hasChild("open", "http://jabber.org/protocol/ibb")
 					|| packet.hasChild("data", "http://jabber.org/protocol/ibb")) {
 				mXmppConnectionService.getJingleConnectionManager()
-						.deliverIbbPacket(account, packet);
+					.deliverIbbPacket(account, packet);
 			} else if (packet.hasChild("query", "http://jabber.org/protocol/disco#info")) {
-				IqPacket response = mXmppConnectionService.getIqGenerator()
-						.discoResponse(packet);
+				final IqPacket response = mXmppConnectionService.getIqGenerator()
+					.discoResponse(packet);
 				account.getXmppConnection().sendIqPacket(response, null);
 			} else if (packet.hasChild("ping", "urn:xmpp:ping")) {
-				IqPacket response = packet.generateRespone(IqPacket.TYPE_RESULT);
+				final IqPacket response = packet.generateRespone(IqPacket.TYPE_RESULT);
 				mXmppConnectionService.sendIqPacket(account, response, null);
 			} else {
 				if ((packet.getType() == IqPacket.TYPE_GET)
 						|| (packet.getType() == IqPacket.TYPE_SET)) {
-					IqPacket response = packet.generateRespone(IqPacket.TYPE_ERROR);
-					Element error = response.addChild("error");
+					final IqPacket response = packet.generateRespone(IqPacket.TYPE_ERROR);
+					final Element error = response.addChild("error");
 					error.setAttribute("type", "cancel");
 					error.addChild("feature-not-implemented",
 							"urn:ietf:params:xml:ns:xmpp-stanzas");
 					account.getXmppConnection().sendIqPacket(response, null);
-				}
+						}
 			}
 		}
 	}
diff --git a/src/main/java/eu/siacs/conversations/persistance/DatabaseBackend.java b/src/main/java/eu/siacs/conversations/persistance/DatabaseBackend.java
index aa07d9c0..7d29314b 100644
--- a/src/main/java/eu/siacs/conversations/persistance/DatabaseBackend.java
+++ b/src/main/java/eu/siacs/conversations/persistance/DatabaseBackend.java
@@ -228,9 +228,9 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 		return conversation;
 	}
 
-	public void updateConversation(Conversation conversation) {
-		SQLiteDatabase db = this.getWritableDatabase();
-		String[] args = { conversation.getUuid() };
+	public void updateConversation(final Conversation conversation) {
+		final SQLiteDatabase db = this.getWritableDatabase();
+		final String[] args = { conversation.getUuid() };
 		db.update(Conversation.TABLENAME, conversation.getContentValues(),
 				Conversation.UUID + "=?", args);
 	}
diff --git a/src/main/java/eu/siacs/conversations/services/MessageArchiveService.java b/src/main/java/eu/siacs/conversations/services/MessageArchiveService.java
index 1a161c56..3fef5703 100644
--- a/src/main/java/eu/siacs/conversations/services/MessageArchiveService.java
+++ b/src/main/java/eu/siacs/conversations/services/MessageArchiveService.java
@@ -236,7 +236,7 @@ public class MessageArchiveService implements OnAdvancedStreamFeaturesLoaded {
 		public Query(Conversation conversation, long start, long end) {
 			this(conversation.getAccount(), start, end);
 			this.conversation = conversation;
-			this.with = conversation.getContactJid().toBareJid();
+			this.with = conversation.getJid().toBareJid();
 		}
 
 		public Query(Conversation conversation, long start, long end, PagingOrder order) {
diff --git a/src/main/java/eu/siacs/conversations/services/XmppConnectionService.java b/src/main/java/eu/siacs/conversations/services/XmppConnectionService.java
index dc3b3200..65c631a1 100644
--- a/src/main/java/eu/siacs/conversations/services/XmppConnectionService.java
+++ b/src/main/java/eu/siacs/conversations/services/XmppConnectionService.java
@@ -35,11 +35,13 @@ import org.openintents.openpgp.util.OpenPgpServiceConnection;
 import java.math.BigInteger;
 import java.security.SecureRandom;
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.Hashtable;
 import java.util.List;
 import java.util.Locale;
+import java.util.Map;
 import java.util.concurrent.CopyOnWriteArrayList;
 
 import de.duenndns.ssl.MemorizingTrustManager;
@@ -47,11 +49,11 @@ import eu.siacs.conversations.Config;
 import eu.siacs.conversations.R;
 import eu.siacs.conversations.crypto.PgpEngine;
 import eu.siacs.conversations.entities.Account;
+import eu.siacs.conversations.entities.Blockable;
 import eu.siacs.conversations.entities.Bookmark;
 import eu.siacs.conversations.entities.Contact;
 import eu.siacs.conversations.entities.Conversation;
 import eu.siacs.conversations.entities.Downloadable;
-import eu.siacs.conversations.entities.DownloadableFile;
 import eu.siacs.conversations.entities.DownloadablePlaceholder;
 import eu.siacs.conversations.entities.Message;
 import eu.siacs.conversations.entities.MucOptions;
@@ -77,7 +79,11 @@ import eu.siacs.conversations.xmpp.OnBindListener;
 import eu.siacs.conversations.xmpp.OnContactStatusChanged;
 import eu.siacs.conversations.xmpp.OnIqPacketReceived;
 import eu.siacs.conversations.xmpp.OnMessageAcknowledged;
+import eu.siacs.conversations.xmpp.OnMessagePacketReceived;
+import eu.siacs.conversations.xmpp.OnPresencePacketReceived;
 import eu.siacs.conversations.xmpp.OnStatusChanged;
+import eu.siacs.conversations.xmpp.OnUpdateBlocklist;
+import eu.siacs.conversations.xmpp.PacketReceived;
 import eu.siacs.conversations.xmpp.XmppConnection;
 import eu.siacs.conversations.xmpp.forms.Data;
 import eu.siacs.conversations.xmpp.forms.Field;
@@ -93,9 +99,10 @@ import eu.siacs.conversations.xmpp.stanzas.PresencePacket;
 
 public class XmppConnectionService extends Service implements OnPhoneContactsLoadedListener {
 
-	public static String ACTION_CLEAR_NOTIFICATION = "clear_notification";
-	private static String ACTION_MERGE_PHONE_CONTACTS = "merge_phone_contacts";
-	public static String ACTION_DISABLE_FOREGROUND = "disable_foreground";
+	public static final String ACTION_CLEAR_NOTIFICATION = "clear_notification";
+	private static final String ACTION_MERGE_PHONE_CONTACTS = "merge_phone_contacts";
+	public static final String ACTION_DISABLE_FOREGROUND = "disable_foreground";
+
 	private ContentObserver contactObserver = new ContentObserver(null) {
 		@Override
 		public void onChange(boolean selfChange) {
@@ -129,13 +136,13 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 	private MemorizingTrustManager mMemorizingTrustManager;
 	private NotificationService mNotificationService = new NotificationService(
 			this);
-	private MessageParser mMessageParser = new MessageParser(this);
-	private PresenceParser mPresenceParser = new PresenceParser(this);
+	private OnMessagePacketReceived mMessageParser = new MessageParser(this);
+	private OnPresencePacketReceived mPresenceParser = new PresenceParser(this);
 	private IqParser mIqParser = new IqParser(this);
 	private MessageGenerator mMessageGenerator = new MessageGenerator(this);
 	private PresenceGenerator mPresenceGenerator = new PresenceGenerator(this);
 	private List<Account> accounts;
-	private final CopyOnWriteArrayList<Conversation> conversations = new CopyOnWriteArrayList<Conversation>();
+	private final List<Conversation> conversations = new CopyOnWriteArrayList<>();
 	private JingleConnectionManager mJingleConnectionManager = new JingleConnectionManager(
 			this);
 	private HttpConnectionManager mHttpConnectionManager = new HttpConnectionManager(
@@ -208,6 +215,8 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 
 	private int accountChangedListenerCount = 0;
 	private OnRosterUpdate mOnRosterUpdate = null;
+	private OnUpdateBlocklist mOnUpdateBlocklist = null;
+	private int updateBlocklistListenerCount = 0;
 	private int rosterChangedListenerCount = 0;
 	private OnMucRosterUpdate mOnMucRosterUpdate = null;
 	private int mucRosterChangedListenerCount = 0;
@@ -354,13 +363,13 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 			@Override
 			public void run() {
 				try {
-					DownloadableFile file = getFileBackend().copyImageToPrivateStorage(message, uri);
+					getFileBackend().copyImageToPrivateStorage(message, uri);
 					if (conversation.getNextEncryption(forceEncryption()) == Message.ENCRYPTION_PGP) {
 						getPgpEngine().encrypt(message, callback);
 					} else {
 						callback.success(message);
 					}
-				} catch (FileBackend.FileCopyException e) {
+				} catch (final FileBackend.FileCopyException e) {
 					callback.error(e.getResId(), message);
 				}
 			}
@@ -573,11 +582,11 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 
 	}
 
-	public XmppConnection createConnection(Account account) {
-		SharedPreferences sharedPref = getPreferences();
+	public XmppConnection createConnection(final Account account) {
+		final SharedPreferences sharedPref = getPreferences();
 		account.setResource(sharedPref.getString("resource", "mobile")
 				.toLowerCase(Locale.getDefault()));
-		XmppConnection connection = new XmppConnection(account, this);
+		final XmppConnection connection = new XmppConnection(account, this);
 		connection.setOnMessagePacketReceivedListener(this.mMessageParser);
 		connection.setOnStatusChangedListener(this.statusListener);
 		connection.setOnPresencePacketReceivedListener(this.mPresenceParser);
@@ -589,10 +598,10 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 		return connection;
 	}
 
-	public void sendMessage(Message message) {
-		Account account = message.getConversation().getAccount();
+	public void sendMessage(final Message message) {
+		final Account account = message.getConversation().getAccount();
 		account.deactivateGracePeriod();
-		Conversation conv = message.getConversation();
+		final Conversation conv = message.getConversation();
 		MessagePacket packet = null;
 		boolean saveInDb = true;
 		boolean send = false;
@@ -694,7 +703,7 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 		updateConversationUi();
 	}
 
-	private void sendUnsentMessages(Conversation conversation) {
+	private void sendUnsentMessages(final Conversation conversation) {
 		conversation.findWaitingMessages(new Conversation.OnMessageFound() {
 
 			@Override
@@ -704,7 +713,7 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 		});
 	}
 
-	private void resendMessage(Message message) {
+	private void resendMessage(final Message message) {
 		Account account = message.getConversation().getAccount();
 		MessagePacket packet = null;
 		if (message.getEncryption() == Message.ENCRYPTION_OTR) {
@@ -731,7 +740,7 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 						} else if (message.getType() == Message.TYPE_IMAGE || message.getType() == Message.TYPE_FILE) {
 							mJingleConnectionManager.createNewConnection(message);
 						}
-					} catch (InvalidJidException e) {
+					} catch (final InvalidJidException ignored) {
 
 					}
 						}
@@ -774,8 +783,8 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 		}
 	}
 
-	public void fetchRosterFromServer(Account account) {
-		IqPacket iqPacket = new IqPacket(IqPacket.TYPE_GET);
+	public void fetchRosterFromServer(final Account account) {
+		final IqPacket iqPacket = new IqPacket(IqPacket.TYPE_GET);
 		if (!"".equals(account.getRosterVersion())) {
 			Log.d(Config.LOGTAG, account.getJid().toBareJid()
 					+ ": fetching roster version " + account.getRosterVersion());
@@ -789,8 +798,8 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 
 					@Override
 					public void onIqPacketReceived(final Account account,
-												   IqPacket packet) {
-						Element query = packet.findChild("query");
+							final IqPacket packet) {
+						final Element query = packet.findChild("query");
 						if (query != null) {
 							account.getRoster().markAllAsNotInRoster();
 							mIqParser.rosterItems(account, query);
@@ -799,22 +808,22 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 				});
 	}
 
-	public void fetchBookmarks(Account account) {
-		IqPacket iqPacket = new IqPacket(IqPacket.TYPE_GET);
-		Element query = iqPacket.query("jabber:iq:private");
+	public void fetchBookmarks(final Account account) {
+		final IqPacket iqPacket = new IqPacket(IqPacket.TYPE_GET);
+		final Element query = iqPacket.query("jabber:iq:private");
 		query.addChild("storage", "storage:bookmarks");
-		OnIqPacketReceived callback = new OnIqPacketReceived() {
+		final PacketReceived callback = new OnIqPacketReceived() {
 
 			@Override
-			public void onIqPacketReceived(Account account, IqPacket packet) {
-				Element query = packet.query();
-				List<Bookmark> bookmarks = new CopyOnWriteArrayList<>();
-				Element storage = query.findChild("storage",
+			public void onIqPacketReceived(final Account account, final IqPacket packet) {
+				final Element query = packet.query();
+				final List<Bookmark> bookmarks = new CopyOnWriteArrayList<>();
+				final Element storage = query.findChild("storage",
 						"storage:bookmarks");
 				if (storage != null) {
-					for (Element item : storage.getChildren()) {
+					for (final Element item : storage.getChildren()) {
 						if (item.getName().equals("conference")) {
-							Bookmark bookmark = Bookmark.parse(item, account);
+							final Bookmark bookmark = Bookmark.parse(item, account);
 							bookmarks.add(bookmark);
 							Conversation conversation = find(bookmark);
 							if (conversation != null) {
@@ -832,7 +841,6 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 			}
 		};
 		sendIqPacket(account, iqPacket, callback);
-
 	}
 
 	public void pushBookmarks(Account account) {
@@ -868,8 +876,8 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 						}
 						final Contact contact = account.getRoster().getContact(jid);
 						String systemAccount = phoneContact.getInt("phoneid")
-								+ "#"
-								+ phoneContact.getString("lookup");
+							+ "#"
+							+ phoneContact.getString("lookup");
 						contact.setSystemAccount(systemAccount);
 						contact.setPhotoUri(phoneContact.getString("photouri"));
 						getAvatarService().clear(contact);
@@ -885,7 +893,7 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 
 	private void initConversations() {
 		synchronized (this.conversations) {
-			Hashtable<String, Account> accountLookupTable = new Hashtable<>();
+			final Map<String, Account> accountLookupTable = new Hashtable<>();
 			for (Account account : this.accounts) {
 				accountLookupTable.put(account.getUuid(), account);
 			}
@@ -992,8 +1000,8 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 		return this.accounts;
 	}
 
-	public Conversation find(List<Conversation> haystack, Contact contact) {
-		for (Conversation conversation : haystack) {
+	public Conversation find(final Iterable<Conversation> haystack, final Contact contact) {
+		for (final Conversation conversation : haystack) {
 			if (conversation.getContact() == contact) {
 				return conversation;
 			}
@@ -1001,15 +1009,13 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 		return null;
 	}
 
-	public Conversation find(final List<Conversation> haystack,
-			final Account account,
-			final Jid jid) {
+	public Conversation find(final Iterable<Conversation> haystack, final Account account, final Jid jid) {
 		if (jid == null ) {
 			return null;
 		}
-		for (Conversation conversation : haystack) {
+		for (final Conversation conversation : haystack) {
 			if ((account == null || conversation.getAccount() == account)
-					&& (conversation.getContactJid().toBareJid().equals(jid.toBareJid()))) {
+					&& (conversation.getJid().toBareJid().equals(jid.toBareJid()))) {
 				return conversation;
 					}
 		}
@@ -1177,7 +1183,7 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 		}
 	}
 
-	public void setOnRosterUpdateListener(OnRosterUpdate listener) {
+	public void setOnRosterUpdateListener(final OnRosterUpdate listener) {
 		synchronized (this) {
 			if (checkListeners()) {
 				switchToForeground();
@@ -1202,6 +1208,31 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 		}
 	}
 
+	public void setOnUpdateBlocklistListener(final OnUpdateBlocklist listener) {
+		synchronized (this) {
+			if (checkListeners()) {
+				switchToForeground();
+			}
+			this.mOnUpdateBlocklist = listener;
+			if (this.updateBlocklistListenerCount < 2) {
+				this.updateBlocklistListenerCount++;
+			}
+		}
+	}
+
+	public void removeOnUpdateBlocklistListener() {
+		synchronized (this) {
+			this.updateBlocklistListenerCount--;
+			if (this.updateBlocklistListenerCount <= 0) {
+				this.updateBlocklistListenerCount = 0;
+				this.mOnUpdateBlocklist = null;
+				if (checkListeners()) {
+					switchToBackground();
+				}
+			}
+		}
+	}
+
 	public void setOnMucRosterUpdateListener(OnMucRosterUpdate listener) {
 		synchronized (this) {
 			if (checkListeners()) {
@@ -1264,7 +1295,7 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 					&& (conversation.getAccount() == account)) {
 				conversation.resetMucOptions();
 				joinMuc(conversation);
-			}
+					}
 		}
 	}
 
@@ -1293,7 +1324,7 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 				packet.addChild("x", "jabber:x:signed").setContent(sig);
 			}
 			sendPresencePacket(account, packet);
-			if (!joinJid.equals(conversation.getContactJid())) {
+			if (!joinJid.equals(conversation.getJid())) {
 				conversation.setContactJid(joinJid);
 				databaseBackend.updateConversation(conversation);
 			}
@@ -1369,14 +1400,14 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 		account.pendingConferenceLeaves.remove(conversation);
 		if (account.getStatus() == Account.State.ONLINE) {
 			PresencePacket packet = new PresencePacket();
-			packet.setTo(conversation.getContactJid());
+			packet.setTo(conversation.getJid());
 			packet.setFrom(conversation.getAccount().getJid());
 			packet.setAttribute("type", "unavailable");
 			sendPresencePacket(conversation.getAccount(), packet);
 			conversation.getMucOptions().setOffline();
 			conversation.deregisterWithBookmark();
 			Log.d(Config.LOGTAG, conversation.getAccount().getJid().toBareJid()
-					+ ": leaving muc " + conversation.getContactJid());
+					+ ": leaving muc " + conversation.getJid());
 		} else {
 			account.pendingConferenceLeaves.add(conversation);
 		}
@@ -1401,7 +1432,7 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 		return null;
 	}
 
-	public void createAdhocConference(final Account account, final List<Jid> jids, final UiCallback<Conversation> callback) {
+	public void createAdhocConference(final Account account, final Iterable<Jid> jids, final UiCallback<Conversation> callback) {
 		Log.d(Config.LOGTAG,account.getJid().toBareJid().toString()+": creating adhoc conference with "+ jids.toString());
 		if (account.getStatus() == Account.State.ONLINE) {
 			try {
@@ -1454,7 +1485,7 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 
 	public void pushConferenceConfiguration(final Conversation conversation,final Bundle options, final OnConferenceOptionsPushed callback) {
 		IqPacket request = new IqPacket(IqPacket.TYPE_GET);
-		request.setTo(conversation.getContactJid().toBareJid());
+		request.setTo(conversation.getJid().toBareJid());
 		request.query("http://jabber.org/protocol/muc#owner");
 		sendIqPacket(conversation.getAccount(),request,new OnIqPacketReceived() {
 			@Override
@@ -1468,7 +1499,7 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 					}
 					data.submit();
 					IqPacket set = new IqPacket(IqPacket.TYPE_SET);
-					set.setTo(conversation.getContactJid().toBareJid());
+					set.setTo(conversation.getJid().toBareJid());
 					set.query("http://jabber.org/protocol/muc#owner").addChild(data);
 					sendIqPacket(account, set, new OnIqPacketReceived() {
 						@Override
@@ -1506,7 +1537,7 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 							if (conversation.endOtrIfNeeded()) {
 								Log.d(Config.LOGTAG, account.getJid().toBareJid()
 										+ ": ended otr session with "
-										+ conversation.getContactJid());
+										+ conversation.getJid());
 							}
 						}
 					}
@@ -1552,8 +1583,8 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 		final Session otrSession = conversation.getOtrSession();
 		Log.d(Config.LOGTAG,
 				account.getJid().toBareJid() + " otr session established with "
-						+ conversation.getContactJid() + "/"
-						+ otrSession.getSessionID().getUserID());
+				+ conversation.getJid() + "/"
+				+ otrSession.getSessionID().getUserID());
 		conversation.findUnsentMessagesWithOtrEncryption(new Conversation.OnMessageFound() {
 
 			@Override
@@ -1698,7 +1729,7 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 			@Override
 			public void onIqPacketReceived(Account account, IqPacket result) {
 				final String ERROR = account.getJid().toBareJid()
-						+ ": fetching avatar for " + avatar.owner + " failed ";
+					+ ": fetching avatar for " + avatar.owner + " failed ";
 				if (result.getType() == IqPacket.TYPE_RESULT) {
 					avatar.image = mIqParser.avatarData(result);
 					if (avatar.image != null) {
@@ -1712,7 +1743,7 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 								updateAccountUi();
 							} else {
 								Contact contact = account.getRoster()
-										.getContact(avatar.owner);
+									.getContact(avatar.owner);
 								contact.setAvatar(avatar.getFilename());
 								getAvatarService().clear(contact);
 								updateConversationUi();
@@ -1848,7 +1879,7 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 			return false;
 		} else {
 			for (Conversation conversation : getConversations()) {
-				if (conversation.getContactJid().equals(recipient)
+				if (conversation.getJid().equals(recipient)
 						&& conversation.getAccount().equals(account)) {
 					return markMessage(conversation, uuid, status);
 						}
@@ -1922,6 +1953,12 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 		}
 	}
 
+	public void updateBlocklistUi(final OnUpdateBlocklist.Status status) {
+		if (mOnUpdateBlocklist != null) {
+			mOnUpdateBlocklist.OnUpdateBlocklist(status);
+		}
+	}
+
 	public void updateMucRosterUi() {
 		if (mOnMucRosterUpdate != null) {
 			mOnMucRosterUpdate.onMucRosterUpdate();
@@ -2034,9 +2071,8 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 		}
 	}
 
-	public void sendIqPacket(Account account, IqPacket packet,
-			OnIqPacketReceived callback) {
-		XmppConnection connection = account.getXmppConnection();
+	public void sendIqPacket(final Account account, final IqPacket packet, final PacketReceived callback) {
+		final XmppConnection connection = account.getXmppConnection();
 		if (connection != null) {
 			connection.sendIqPacket(packet, callback);
 		}
@@ -2054,6 +2090,8 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 		return this.mIqGenerator;
 	}
 
+	public IqParser getIqParser() { return this.mIqParser; }
+
 	public JingleConnectionManager getJingleConnectionManager() {
 		return this.mJingleConnectionManager;
 	}
@@ -2083,8 +2121,8 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 		return this.mHttpConnectionManager;
 	}
 
-	public void resendFailedMessages(Message message) {
-		List<Message> messages = new ArrayList<>();
+	public void resendFailedMessages(final Message message) {
+		final Collection<Message> messages = new ArrayList<>();
 		Message current = message;
 		while (current.getStatus() == Message.STATUS_SEND_FAILED) {
 			messages.add(current);
@@ -2094,7 +2132,7 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 				break;
 			}
 		}
-		for (Message msg : messages) {
+		for (final Message msg : messages) {
 			markMessage(msg, Message.STATUS_WAITING);
 			this.resendMessage(msg);
 		}
@@ -2136,4 +2174,35 @@ public class XmppConnectionService extends Service implements OnPhoneContactsLoa
 			return XmppConnectionService.this;
 		}
 	}
+
+	public void sendBlockRequest(final Blockable blockable) {
+		if (blockable != null && blockable.getBlockedJid() != null) {
+			final Jid jid = blockable.getBlockedJid();
+			this.sendIqPacket(blockable.getAccount(), getIqGenerator().generateSetBlockRequest(jid), new OnIqPacketReceived() {
+
+				@Override
+				public void onIqPacketReceived(final Account account, final IqPacket packet) {
+					if (packet.getType() == IqPacket.TYPE_RESULT) {
+						account.getBlocklist().add(jid);
+						updateBlocklistUi(OnUpdateBlocklist.Status.BLOCKED);
+					}
+				}
+			});
+		}
+	}
+
+	public void sendUnblockRequest(final Blockable blockable) {
+		if (blockable != null && blockable.getJid() != null) {
+			final Jid jid = blockable.getBlockedJid();
+			this.sendIqPacket(blockable.getAccount(), getIqGenerator().generateSetUnblockRequest(jid), new OnIqPacketReceived() {
+				@Override
+				public void onIqPacketReceived(final Account account, final IqPacket packet) {
+					if (packet.getType() == IqPacket.TYPE_RESULT) {
+						account.getBlocklist().remove(jid);
+						updateBlocklistUi(OnUpdateBlocklist.Status.UNBLOCKED);
+					}
+				}
+			});
+		}
+	}
 }
diff --git a/src/main/java/eu/siacs/conversations/ui/AbstractSearchableListItemActivity.java b/src/main/java/eu/siacs/conversations/ui/AbstractSearchableListItemActivity.java
new file mode 100644
index 00000000..1a9fc95c
--- /dev/null
+++ b/src/main/java/eu/siacs/conversations/ui/AbstractSearchableListItemActivity.java
@@ -0,0 +1,124 @@
+package eu.siacs.conversations.ui;
+
+import android.content.Context;
+import android.os.Bundle;
+import android.text.Editable;
+import android.text.TextWatcher;
+import android.view.Menu;
+import android.view.MenuItem;
+import android.view.View;
+import android.view.inputmethod.InputMethodManager;
+import android.widget.ArrayAdapter;
+import android.widget.EditText;
+import android.widget.ListView;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import eu.siacs.conversations.R;
+import eu.siacs.conversations.entities.ListItem;
+import eu.siacs.conversations.ui.adapter.ListItemAdapter;
+
+public abstract class AbstractSearchableListItemActivity extends XmppActivity {
+	private ListView mListView;
+	private final List<ListItem> listItems = new ArrayList<>();
+	private ArrayAdapter<ListItem> mListItemsAdapter;
+
+	private EditText mSearchEditText;
+
+	private final MenuItem.OnActionExpandListener mOnActionExpandListener = new MenuItem.OnActionExpandListener() {
+
+		@Override
+		public boolean onMenuItemActionExpand(final MenuItem item) {
+			mSearchEditText.post(new Runnable() {
+
+				@Override
+				public void run() {
+					mSearchEditText.requestFocus();
+					final InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
+					imm.showSoftInput(mSearchEditText,
+							InputMethodManager.SHOW_IMPLICIT);
+				}
+			});
+
+			return true;
+		}
+
+		@Override
+		public boolean onMenuItemActionCollapse(final MenuItem item) {
+			final InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
+			imm.hideSoftInputFromWindow(mSearchEditText.getWindowToken(),
+					InputMethodManager.HIDE_IMPLICIT_ONLY);
+			mSearchEditText.setText("");
+			filterContacts();
+			return true;
+		}
+	};
+
+	private final TextWatcher mSearchTextWatcher = new TextWatcher() {
+
+		@Override
+		public void afterTextChanged(final Editable editable) {
+			filterContacts(editable.toString());
+		}
+
+		@Override
+		public void beforeTextChanged(final CharSequence s, final int start, final int count,
+				final int after) {
+		}
+
+		@Override
+		public void onTextChanged(final CharSequence s, final int start, final int before,
+				final int count) {
+		}
+	};
+
+	public ListView getListView() {
+		return mListView;
+	}
+
+	public List<ListItem> getListItems() {
+		return listItems;
+	}
+
+	public EditText getSearchEditText() {
+		return mSearchEditText;
+	}
+
+	public ArrayAdapter<ListItem> getListItemAdapter() {
+		return mListItemsAdapter;
+	}
+
+	@Override
+	public void onCreate(final Bundle savedInstanceState) {
+		super.onCreate(savedInstanceState);
+		setContentView(R.layout.activity_choose_contact);
+		mListView = (ListView) findViewById(R.id.choose_contact_list);
+		mListView.setFastScrollEnabled(true);
+		mListItemsAdapter = new ListItemAdapter(this, listItems);
+		mListView.setAdapter(mListItemsAdapter);
+	}
+
+	@Override
+	public boolean onCreateOptionsMenu(final Menu menu) {
+		getMenuInflater().inflate(R.menu.choose_contact, menu);
+		final MenuItem menuSearchView = menu.findItem(R.id.action_search);
+		final View mSearchView = menuSearchView.getActionView();
+		mSearchEditText = (EditText) mSearchView
+			.findViewById(R.id.search_field);
+		mSearchEditText.addTextChangedListener(mSearchTextWatcher);
+		menuSearchView.setOnActionExpandListener(mOnActionExpandListener);
+		return true;
+	}
+
+	protected void filterContacts() {
+		filterContacts(null);
+	}
+
+	protected abstract void filterContacts(final String needle);
+
+	@Override
+	void onBackendConnected() {
+		filterContacts();
+	}
+}
diff --git a/src/main/java/eu/siacs/conversations/ui/BlockContactDialog.java b/src/main/java/eu/siacs/conversations/ui/BlockContactDialog.java
new file mode 100644
index 00000000..9cf7e9f8
--- /dev/null
+++ b/src/main/java/eu/siacs/conversations/ui/BlockContactDialog.java
@@ -0,0 +1,41 @@
+package eu.siacs.conversations.ui;
+
+import android.app.AlertDialog;
+import android.content.Context;
+import android.content.DialogInterface;
+
+import eu.siacs.conversations.R;
+import eu.siacs.conversations.entities.Blockable;
+import eu.siacs.conversations.services.XmppConnectionService;
+
+public final class BlockContactDialog {
+	public static void show(final Context context,
+			final XmppConnectionService xmppConnectionService,
+			final Blockable blockable) {
+		final AlertDialog.Builder builder = new AlertDialog.Builder(context);
+		final boolean isBlocked = blockable.isBlocked();
+		builder.setNegativeButton(R.string.cancel, null);
+
+		if (blockable.getJid().isDomainJid() || blockable.getAccount().isBlocked(blockable.getJid().toDomainJid())) {
+			builder.setTitle(isBlocked ? R.string.action_unblock_domain : R.string.action_block_domain);
+			builder.setMessage(context.getResources().getString(isBlocked ? R.string.unblock_domain_text : R.string.block_domain_text,
+						blockable.getJid().toDomainJid()));
+		} else {
+			builder.setTitle(isBlocked ? R.string.action_unblock_contact : R.string.action_block_contact);
+			builder.setMessage(context.getResources().getString(isBlocked ? R.string.unblock_contact_text : R.string.block_contact_text,
+						blockable.getJid().toBareJid()));
+		}
+		builder.setPositiveButton(isBlocked ? R.string.unblock : R.string.block, new DialogInterface.OnClickListener() {
+
+			@Override
+			public void onClick(final DialogInterface dialog, final int which) {
+				if (isBlocked) {
+					xmppConnectionService.sendUnblockRequest(blockable);
+				} else {
+					xmppConnectionService.sendBlockRequest(blockable);
+				}
+			}
+		});
+		builder.create().show();
+	}
+}
diff --git a/src/main/java/eu/siacs/conversations/ui/BlocklistActivity.java b/src/main/java/eu/siacs/conversations/ui/BlocklistActivity.java
new file mode 100644
index 00000000..13d7f4fc
--- /dev/null
+++ b/src/main/java/eu/siacs/conversations/ui/BlocklistActivity.java
@@ -0,0 +1,75 @@
+package eu.siacs.conversations.ui;
+
+import android.os.Bundle;
+import android.text.Editable;
+import android.view.View;
+import android.widget.AdapterView;
+
+import java.util.Collections;
+
+import eu.siacs.conversations.entities.Account;
+import eu.siacs.conversations.entities.Contact;
+import eu.siacs.conversations.xmpp.OnUpdateBlocklist;
+import eu.siacs.conversations.xmpp.jid.Jid;
+
+public class BlocklistActivity extends AbstractSearchableListItemActivity implements OnUpdateBlocklist {
+
+	private Account account = null;
+
+	@Override
+	public void onCreate(final Bundle savedInstanceState) {
+		super.onCreate(savedInstanceState);
+		getListView().setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
+
+			@Override
+			public boolean onItemLongClick(final AdapterView<?> parent,
+					final View view,
+					final int position,
+					final long id) {
+				BlockContactDialog.show(parent.getContext(), xmppConnectionService,(Contact) getListItems().get(position));
+				return true;
+			}
+		});
+	}
+
+	@Override
+	public void onBackendConnected() {
+		for (final Account account : xmppConnectionService.getAccounts()) {
+			if (account.getJid().toString().equals(getIntent().getStringExtra("account"))) {
+				this.account = account;
+				break;
+			}
+		}
+		filterContacts();
+	}
+
+	@Override
+	protected void filterContacts(final String needle) {
+		getListItems().clear();
+		if (account != null) {
+			for (final Jid jid : account.getBlocklist()) {
+				final Contact contact = account.getRoster().getContact(jid);
+				if (contact.match(needle) && contact.isBlocked()) {
+					getListItems().add(contact);
+				}
+			}
+			Collections.sort(getListItems());
+		}
+		runOnUiThread(new Runnable() {
+			@Override
+			public void run() {
+				getListItemAdapter().notifyDataSetChanged();
+			}
+		});
+	}
+
+	@Override
+	public void OnUpdateBlocklist(final OnUpdateBlocklist.Status status) {
+		final Editable editable = getSearchEditText().getText();
+		if (editable != null) {
+			filterContacts(editable.toString());
+		} else {
+			filterContacts();
+		}
+	}
+}
diff --git a/src/main/java/eu/siacs/conversations/ui/ChooseContactActivity.java b/src/main/java/eu/siacs/conversations/ui/ChooseContactActivity.java
index e7254933..70b353c6 100644
--- a/src/main/java/eu/siacs/conversations/ui/ChooseContactActivity.java
+++ b/src/main/java/eu/siacs/conversations/ui/ChooseContactActivity.java
@@ -1,101 +1,33 @@
 package eu.siacs.conversations.ui;
 
-import java.util.ArrayList;
-import java.util.Collections;
-
 import android.content.Context;
 import android.content.Intent;
 import android.os.Bundle;
-import android.text.Editable;
-import android.text.TextWatcher;
-import android.view.Menu;
-import android.view.MenuItem;
 import android.view.View;
 import android.view.inputmethod.InputMethodManager;
 import android.widget.AdapterView;
-import android.widget.ArrayAdapter;
-import android.widget.EditText;
-import android.widget.ListView;
-import eu.siacs.conversations.R;
+
+import java.util.Collections;
+
 import eu.siacs.conversations.entities.Account;
 import eu.siacs.conversations.entities.Contact;
 import eu.siacs.conversations.entities.ListItem;
-import eu.siacs.conversations.ui.adapter.ListItemAdapter;
-
-public class ChooseContactActivity extends XmppActivity {
-
-	private ListView mListView;
-	private ArrayList<ListItem> contacts = new ArrayList<>();
-	private ArrayAdapter<ListItem> mContactsAdapter;
-
-	private EditText mSearchEditText;
-
-	private TextWatcher mSearchTextWatcher = new TextWatcher() {
-
-		@Override
-		public void afterTextChanged(Editable editable) {
-			filterContacts(editable.toString());
-		}
-
-		@Override
-		public void beforeTextChanged(CharSequence s, int start, int count,
-				int after) {
-		}
-
-		@Override
-		public void onTextChanged(CharSequence s, int start, int before,
-				int count) {
-		}
-	};
-
-	private MenuItem.OnActionExpandListener mOnActionExpandListener = new MenuItem.OnActionExpandListener() {
-
-		@Override
-		public boolean onMenuItemActionExpand(MenuItem item) {
-			mSearchEditText.post(new Runnable() {
-
-				@Override
-				public void run() {
-					mSearchEditText.requestFocus();
-					InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
-					imm.showSoftInput(mSearchEditText,
-							InputMethodManager.SHOW_IMPLICIT);
-				}
-			});
-
-			return true;
-		}
-
-		@Override
-		public boolean onMenuItemActionCollapse(MenuItem item) {
-			InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
-			imm.hideSoftInputFromWindow(mSearchEditText.getWindowToken(),
-					InputMethodManager.HIDE_IMPLICIT_ONLY);
-			mSearchEditText.setText("");
-			filterContacts(null);
-			return true;
-		}
-	};
 
+public class ChooseContactActivity extends AbstractSearchableListItemActivity {
 	@Override
-	public void onCreate(Bundle savedInstanceState) {
+	public void onCreate(final Bundle savedInstanceState) {
 		super.onCreate(savedInstanceState);
-		setContentView(R.layout.activity_choose_contact);
-		mListView = (ListView) findViewById(R.id.choose_contact_list);
-		mListView.setFastScrollEnabled(true);
-		mContactsAdapter = new ListItemAdapter(this, contacts);
-		mListView.setAdapter(mContactsAdapter);
-		mListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
+		getListView().setOnItemClickListener(new AdapterView.OnItemClickListener() {
 
 			@Override
-			public void onItemClick(AdapterView<?> arg0, View arg1,
-					int position, long arg3) {
-				InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
-				imm.hideSoftInputFromWindow(mSearchEditText.getWindowToken(),
+			public void onItemClick(final AdapterView<?> parent, final View view,
+					final int position, final long id) {
+				final InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
+				imm.hideSoftInputFromWindow(getSearchEditText().getWindowToken(),
 						InputMethodManager.HIDE_IMPLICIT_ONLY);
-				Intent request = getIntent();
-				Intent data = new Intent();
-				ListItem mListItem = contacts.get(position);
+				final Intent request = getIntent();
+				final Intent data = new Intent();
+				final ListItem mListItem = getListItems().get(position);
 				data.putExtra("contact", mListItem.getJid().toString());
 				String account = request.getStringExtra("account");
 				if (account == null && mListItem instanceof Contact) {
@@ -108,38 +40,21 @@ public class ChooseContactActivity extends XmppActivity {
 				finish();
 			}
 		});
-	}
 
-	@Override
-	public boolean onCreateOptionsMenu(Menu menu) {
-		getMenuInflater().inflate(R.menu.choose_contact, menu);
-		MenuItem menuSearchView = menu.findItem(R.id.action_search);
-		View mSearchView = menuSearchView.getActionView();
-		mSearchEditText = (EditText) mSearchView
-				.findViewById(R.id.search_field);
-		mSearchEditText.addTextChangedListener(mSearchTextWatcher);
-		menuSearchView.setOnActionExpandListener(mOnActionExpandListener);
-		return true;
 	}
 
-	@Override
-	void onBackendConnected() {
-		filterContacts(null);
-	}
-
-	protected void filterContacts(String needle) {
-		this.contacts.clear();
-		for (Account account : xmppConnectionService.getAccounts()) {
+	protected void filterContacts(final String needle) {
+		getListItems().clear();
+		for (final Account account : xmppConnectionService.getAccounts()) {
 			if (account.getStatus() != Account.State.DISABLED) {
-				for (Contact contact : account.getRoster().getContacts()) {
+				for (final Contact contact : account.getRoster().getContacts()) {
 					if (contact.showInRoster() && contact.match(needle)) {
-						this.contacts.add(contact);
+						getListItems().add(contact);
 					}
 				}
 			}
 		}
-		Collections.sort(this.contacts);
-		mContactsAdapter.notifyDataSetChanged();
+		Collections.sort(getListItems());
+		getListItemAdapter().notifyDataSetChanged();
 	}
-
 }
diff --git a/src/main/java/eu/siacs/conversations/ui/ConferenceDetailsActivity.java b/src/main/java/eu/siacs/conversations/ui/ConferenceDetailsActivity.java
index 2e36c545..eeb015f3 100644
--- a/src/main/java/eu/siacs/conversations/ui/ConferenceDetailsActivity.java
+++ b/src/main/java/eu/siacs/conversations/ui/ConferenceDetailsActivity.java
@@ -157,8 +157,8 @@ public class ConferenceDetailsActivity extends XmppActivity implements OnConvers
 						@Override
 						public void onValueEdited(String value) {
 							MessagePacket packet = xmppConnectionService
-									.getMessageGenerator().conferenceSubject(
-											mConversation, value);
+								.getMessageGenerator().conferenceSubject(
+										mConversation, value);
 							xmppConnectionService.sendMessagePacket(
 									mConversation.getAccount(), packet);
 						}
@@ -191,7 +191,7 @@ public class ConferenceDetailsActivity extends XmppActivity implements OnConvers
 	@Override
 	protected String getShareableUri() {
 		if (mConversation != null) {
-			return "xmpp:" + mConversation.getContactJid().toBareJid().toString() + "?join";
+			return "xmpp:" + mConversation.getJid().toBareJid().toString() + "?join";
 		} else {
 			return "";
 		}
@@ -202,7 +202,7 @@ public class ConferenceDetailsActivity extends XmppActivity implements OnConvers
 		MenuItem menuItemSaveBookmark = menu.findItem(R.id.action_save_as_bookmark);
 		MenuItem menuItemDeleteBookmark = menu.findItem(R.id.action_delete_bookmark);
 		Account account = mConversation.getAccount();
-		if (account.hasBookmarkFor(mConversation.getContactJid().toBareJid())) {
+		if (account.hasBookmarkFor(mConversation.getJid().toBareJid())) {
 			menuItemSaveBookmark.setVisible(false);
 			menuItemDeleteBookmark.setVisible(true);
 		} else {
@@ -263,9 +263,9 @@ public class ConferenceDetailsActivity extends XmppActivity implements OnConvers
 
 	protected void saveAsBookmark() {
 		Account account = mConversation.getAccount();
-		Bookmark bookmark = new Bookmark(account, mConversation.getContactJid().toBareJid());
-		if (!mConversation.getContactJid().isBareJid()) {
-			bookmark.setNick(mConversation.getContactJid().getResourcepart());
+		Bookmark bookmark = new Bookmark(account, mConversation.getJid().toBareJid());
+		if (!mConversation.getJid().isBareJid()) {
+			bookmark.setNick(mConversation.getJid().getResourcepart());
 		}
 		bookmark.setAutojoin(true);
 		account.getBookmarks().add(bookmark);
@@ -288,7 +288,7 @@ public class ConferenceDetailsActivity extends XmppActivity implements OnConvers
 		}
 		if (uuid != null) {
 			this.mConversation = xmppConnectionService
-					.findConversationByUuid(uuid);
+				.findConversationByUuid(uuid);
 			if (this.mConversation != null) {
 				populateView();
 			}
@@ -297,11 +297,11 @@ public class ConferenceDetailsActivity extends XmppActivity implements OnConvers
 
 	private void populateView() {
 		mAccountJid.setText(getString(R.string.using_account, mConversation
-				.getAccount().getJid().toBareJid()));
+					.getAccount().getJid().toBareJid()));
 		mYourPhoto.setImageBitmap(avatarService().get(
-				mConversation.getAccount(), getPixel(48)));
+					mConversation.getAccount(), getPixel(48)));
 		setTitle(mConversation.getName());
-		mFullJid.setText(mConversation.getContactJid().toBareJid().toString());
+		mFullJid.setText(mConversation.getJid().toBareJid().toString());
 		mYourNick.setText(mConversation.getMucOptions().getActualNick());
 		mRoleAffiliaton = (TextView) findViewById(R.id.muc_role);
 		if (mConversation.getMucOptions().online()) {
@@ -338,7 +338,7 @@ public class ConferenceDetailsActivity extends XmppActivity implements OnConvers
 			registerForContextMenu(view);
 			view.setTag(user);
 			TextView name = (TextView) view
-					.findViewById(R.id.contact_display_name);
+				.findViewById(R.id.contact_display_name);
 			TextView key = (TextView) view.findViewById(R.id.key);
 			TextView role = (TextView) view.findViewById(R.id.contact_jid);
 			if (user.getPgpKeyId() != 0) {
diff --git a/src/main/java/eu/siacs/conversations/ui/ContactDetailsActivity.java b/src/main/java/eu/siacs/conversations/ui/ContactDetailsActivity.java
index 4259371a..b195f2f1 100644
--- a/src/main/java/eu/siacs/conversations/ui/ContactDetailsActivity.java
+++ b/src/main/java/eu/siacs/conversations/ui/ContactDetailsActivity.java
@@ -38,10 +38,11 @@ import eu.siacs.conversations.entities.ListItem;
 import eu.siacs.conversations.services.XmppConnectionService.OnAccountUpdate;
 import eu.siacs.conversations.services.XmppConnectionService.OnRosterUpdate;
 import eu.siacs.conversations.utils.UIHelper;
+import eu.siacs.conversations.xmpp.OnUpdateBlocklist;
 import eu.siacs.conversations.xmpp.jid.InvalidJidException;
 import eu.siacs.conversations.xmpp.jid.Jid;
 
-public class ContactDetailsActivity extends XmppActivity implements OnAccountUpdate, OnRosterUpdate {
+public class ContactDetailsActivity extends XmppActivity implements OnAccountUpdate, OnRosterUpdate, OnUpdateBlocklist {
 	public static final String ACTION_VIEW_CONTACT = "view_contact";
 
 	private Contact contact;
@@ -50,7 +51,7 @@ public class ContactDetailsActivity extends XmppActivity implements OnAccountUpd
 		@Override
 		public void onClick(DialogInterface dialog, int which) {
 			ContactDetailsActivity.this.xmppConnectionService
-					.deleteContactOnServer(contact);
+				.deleteContactOnServer(contact);
 			ContactDetailsActivity.this.finish();
 		}
 	};
@@ -58,14 +59,14 @@ public class ContactDetailsActivity extends XmppActivity implements OnAccountUpd
 
 		@Override
 		public void onCheckedChanged(CompoundButton buttonView,
-									 boolean isChecked) {
+				boolean isChecked) {
 			if (isChecked) {
 				if (contact
 						.getOption(Contact.Options.PENDING_SUBSCRIPTION_REQUEST)) {
 					xmppConnectionService.sendPresencePacket(contact
-									.getAccount(),
+							.getAccount(),
 							xmppConnectionService.getPresenceGenerator()
-									.sendPresenceUpdatesTo(contact));
+							.sendPresenceUpdatesTo(contact));
 				} else {
 					contact.setOption(Contact.Options.PREEMPTIVE_GRANT);
 				}
@@ -73,7 +74,7 @@ public class ContactDetailsActivity extends XmppActivity implements OnAccountUpd
 				contact.resetOption(Contact.Options.PREEMPTIVE_GRANT);
 				xmppConnectionService.sendPresencePacket(contact.getAccount(),
 						xmppConnectionService.getPresenceGenerator()
-								.stopPresenceUpdatesTo(contact));
+						.stopPresenceUpdatesTo(contact));
 			}
 		}
 	};
@@ -81,15 +82,15 @@ public class ContactDetailsActivity extends XmppActivity implements OnAccountUpd
 
 		@Override
 		public void onCheckedChanged(CompoundButton buttonView,
-									 boolean isChecked) {
+				boolean isChecked) {
 			if (isChecked) {
 				xmppConnectionService.sendPresencePacket(contact.getAccount(),
 						xmppConnectionService.getPresenceGenerator()
-								.requestPresenceUpdatesFrom(contact));
+						.requestPresenceUpdatesFrom(contact));
 			} else {
 				xmppConnectionService.sendPresencePacket(contact.getAccount(),
 						xmppConnectionService.getPresenceGenerator()
-								.stopPresenceUpdatesFrom(contact));
+						.stopPresenceUpdatesFrom(contact));
 			}
 		}
 	};
@@ -127,7 +128,7 @@ public class ContactDetailsActivity extends XmppActivity implements OnAccountUpd
 					ContactDetailsActivity.this);
 			builder.setTitle(getString(R.string.action_add_phone_book));
 			builder.setMessage(getString(R.string.add_phone_book_text,
-					contact.getJid()));
+						contact.getJid()));
 			builder.setNegativeButton(getString(R.string.cancel), null);
 			builder.setPositiveButton(getString(R.string.add), addToPhonebook);
 			builder.create().show();
@@ -166,7 +167,7 @@ public class ContactDetailsActivity extends XmppActivity implements OnAccountUpd
 	}
 
 	@Override
-	protected void onCreate(Bundle savedInstanceState) {
+	protected void onCreate(final Bundle savedInstanceState) {
 		super.onCreate(savedInstanceState);
 		if (getIntent().getAction().equals(ACTION_VIEW_CONTACT)) {
 			try {
@@ -188,15 +189,17 @@ public class ContactDetailsActivity extends XmppActivity implements OnAccountUpd
 		badge = (QuickContactBadge) findViewById(R.id.details_contact_badge);
 		keys = (LinearLayout) findViewById(R.id.details_contact_keys);
 		tags = (LinearLayout) findViewById(R.id.tags);
-		getActionBar().setHomeButtonEnabled(true);
-		getActionBar().setDisplayHomeAsUpEnabled(true);
+		if (getActionBar() != null) {
+			getActionBar().setHomeButtonEnabled(true);
+			getActionBar().setDisplayHomeAsUpEnabled(true);
+		}
 
-		SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(this);
+		final SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(this);
 		this.showDynamicTags = preferences.getBoolean("show_dynamic_tags",false);
 	}
 
 	@Override
-	public boolean onOptionsItemSelected(MenuItem menuItem) {
+	public boolean onOptionsItemSelected(final MenuItem menuItem) {
 		AlertDialog.Builder builder = new AlertDialog.Builder(this);
 		builder.setNegativeButton(getString(R.string.cancel), null);
 		switch (menuItem.getItemId()) {
@@ -205,11 +208,11 @@ public class ContactDetailsActivity extends XmppActivity implements OnAccountUpd
 				break;
 			case R.id.action_delete_contact:
 				builder.setTitle(getString(R.string.action_delete_contact))
-						.setMessage(
-								getString(R.string.remove_contact_text,
-										contact.getJid()))
-						.setPositiveButton(getString(R.string.delete),
-								removeFromRoster).create().show();
+					.setMessage(
+							getString(R.string.remove_contact_text,
+								contact.getJid()))
+					.setPositiveButton(getString(R.string.delete),
+							removeFromRoster).create().show();
 				break;
 			case R.id.action_edit_contact:
 				if (contact.getSystemAccount() == null) {
@@ -219,7 +222,7 @@ public class ContactDetailsActivity extends XmppActivity implements OnAccountUpd
 						public void onValueEdited(String value) {
 							contact.setServerName(value);
 							ContactDetailsActivity.this.xmppConnectionService
-									.pushContactToServer(contact);
+								.pushContactToServer(contact);
 							populateView();
 						}
 					});
@@ -285,7 +288,7 @@ public class ContactDetailsActivity extends XmppActivity implements OnAccountUpd
 		receive.setOnCheckedChangeListener(this.mOnReceiveCheckedChange);
 
 		lastseen.setText(UIHelper.lastseen(getApplicationContext(),
-				contact.lastseen.time));
+					contact.lastseen.time));
 
 		if (contact.getPresences().size() > 1) {
 			contactJidTv.setText(contact.getJid() + " ("
@@ -294,7 +297,7 @@ public class ContactDetailsActivity extends XmppActivity implements OnAccountUpd
 			contactJidTv.setText(contact.getJid().toString());
 		}
 		accountJidTv.setText(getString(R.string.using_account, contact
-				.getAccount().getJid().toBareJid()));
+					.getAccount().getJid().toBareJid()));
 		prepareContactBadge(badge, contact);
 		if (contact.getSystemAccount() == null) {
 			badge.setOnClickListener(onBadgeClick);
@@ -309,7 +312,7 @@ public class ContactDetailsActivity extends XmppActivity implements OnAccountUpd
 			TextView key = (TextView) view.findViewById(R.id.key);
 			TextView keyType = (TextView) view.findViewById(R.id.key_type);
 			ImageButton remove = (ImageButton) view
-					.findViewById(R.id.button_remove);
+				.findViewById(R.id.button_remove);
 			remove.setVisibility(View.VISIBLE);
 			keyType.setText("OTR Fingerprint");
 			key.setText(otrFingerprint);
@@ -334,7 +337,7 @@ public class ContactDetailsActivity extends XmppActivity implements OnAccountUpd
 				@Override
 				public void onClick(View v) {
 					PgpEngine pgp = ContactDetailsActivity.this.xmppConnectionService
-							.getPgpEngine();
+						.getPgpEngine();
 					if (pgp != null) {
 						PendingIntent intent = pgp.getIntentForKey(contact);
 						if (intent != null) {
@@ -363,8 +366,8 @@ public class ContactDetailsActivity extends XmppActivity implements OnAccountUpd
 		} else {
 			tags.setVisibility(View.VISIBLE);
 			tags.removeAllViewsInLayout();
-			for(ListItem.Tag tag : tagList) {
-				TextView tv = (TextView) inflater.inflate(R.layout.list_item_tag,tags,false);
+			for(final ListItem.Tag tag : tagList) {
+				final TextView tv = (TextView) inflater.inflate(R.layout.list_item_tag,tags,false);
 				tv.setText(tag.getName());
 				tv.setBackgroundColor(tag.getColor());
 				tags.addView(tv);
@@ -406,7 +409,7 @@ public class ContactDetailsActivity extends XmppActivity implements OnAccountUpd
 	public void onBackendConnected() {
 		if ((accountJid != null) && (contactJid != null)) {
 			Account account = xmppConnectionService
-					.findAccountByJid(accountJid);
+				.findAccountByJid(accountJid);
 			if (account == null) {
 				return;
 			}
@@ -414,4 +417,15 @@ public class ContactDetailsActivity extends XmppActivity implements OnAccountUpd
 			populateView();
 		}
 	}
+
+	@Override
+	public void OnUpdateBlocklist(final Status status) {
+		runOnUiThread(new Runnable() {
+
+			@Override
+			public void run() {
+				populateView();
+			}
+		});
+	}
 }
diff --git a/src/main/java/eu/siacs/conversations/ui/ConversationActivity.java b/src/main/java/eu/siacs/conversations/ui/ConversationActivity.java
index 6656de2b..3a3f0778 100644
--- a/src/main/java/eu/siacs/conversations/ui/ConversationActivity.java
+++ b/src/main/java/eu/siacs/conversations/ui/ConversationActivity.java
@@ -15,7 +15,6 @@ import android.os.SystemClock;
 import android.provider.MediaStore;
 import android.support.v4.widget.SlidingPaneLayout;
 import android.support.v4.widget.SlidingPaneLayout.PanelSlideListener;
-import android.view.KeyEvent;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.View;
@@ -32,6 +31,7 @@ import java.util.ArrayList;
 import java.util.List;
 
 import eu.siacs.conversations.R;
+import eu.siacs.conversations.entities.Blockable;
 import eu.siacs.conversations.entities.Contact;
 import eu.siacs.conversations.entities.Conversation;
 import eu.siacs.conversations.entities.Message;
@@ -40,9 +40,10 @@ import eu.siacs.conversations.services.XmppConnectionService.OnConversationUpdat
 import eu.siacs.conversations.services.XmppConnectionService.OnRosterUpdate;
 import eu.siacs.conversations.ui.adapter.ConversationAdapter;
 import eu.siacs.conversations.utils.ExceptionHelper;
+import eu.siacs.conversations.xmpp.OnUpdateBlocklist;
 
-public class ConversationActivity extends XmppActivity implements
-		OnAccountUpdate, OnConversationUpdate, OnRosterUpdate {
+public class ConversationActivity extends XmppActivity
+	implements OnAccountUpdate, OnConversationUpdate, OnRosterUpdate, OnUpdateBlocklist {
 
 	public static final String VIEW_CONVERSATION = "viewConversation";
 	public static final String CONVERSATION = "conversationUuid";
@@ -144,12 +145,12 @@ public class ConversationActivity extends XmppActivity implements
 	protected void onCreate(Bundle savedInstanceState) {
 		super.onCreate(savedInstanceState);
 		if (savedInstanceState != null) {mOpenConverstaion = savedInstanceState.getString(
-					STATE_OPEN_CONVERSATION, null);
-			mPanelOpen = savedInstanceState.getBoolean(STATE_PANEL_OPEN, true);
-			String pending = savedInstanceState.getString(STATE_PENDING_URI, null);
-			if (pending != null) {
-				mPendingImageUri = Uri.parse(pending);
-			}
+				STATE_OPEN_CONVERSATION, null);
+		mPanelOpen = savedInstanceState.getBoolean(STATE_PANEL_OPEN, true);
+		String pending = savedInstanceState.getString(STATE_PENDING_URI, null);
+		if (pending != null) {
+			mPendingImageUri = Uri.parse(pending);
+		}
 		}
 
 		setContentView(R.layout.fragment_conversations_overview);
@@ -172,7 +173,7 @@ public class ConversationActivity extends XmppActivity implements
 
 			@Override
 			public void onItemClick(AdapterView<?> arg0, View clickedView,
-									int position, long arg3) {
+					int position, long arg3) {
 				if (getSelectedConversation() != conversationList.get(position)) {
 					setSelectedConversation(conversationList.get(position));
 					ConversationActivity.this.mConversationFragment.reInit(getSelectedConversation());
@@ -188,7 +189,7 @@ public class ConversationActivity extends XmppActivity implements
 			SlidingPaneLayout mSlidingPaneLayout = (SlidingPaneLayout) mContentView;
 			mSlidingPaneLayout.setParallaxDistance(150);
 			mSlidingPaneLayout
-					.setShadowResource(R.drawable.es_slidingpane_shadow);
+				.setShadowResource(R.drawable.es_slidingpane_shadow);
 			mSlidingPaneLayout.setSliderFadeColor(0);
 			mSlidingPaneLayout.setPanelSlideListener(new PanelSlideListener() {
 
@@ -199,7 +200,7 @@ public class ConversationActivity extends XmppActivity implements
 					hideKeyboard();
 					if (xmppConnectionServiceBound) {
 						xmppConnectionService.getNotificationService()
-								.setOpenConversation(null);
+							.setOpenConversation(null);
 					}
 					closeContextMenu();
 				}
@@ -244,7 +245,7 @@ public class ConversationActivity extends XmppActivity implements
 				if (conversation.getMode() == Conversation.MODE_SINGLE || useSubjectToIdentifyConference()) {
 					ab.setTitle(conversation.getName());
 				} else {
-					ab.setTitle(conversation.getContactJid().toBareJid().toString());
+					ab.setTitle(conversation.getJid().toBareJid().toString());
 				}
 			} else {
 				ab.setDisplayHomeAsUpEnabled(false);
@@ -269,17 +270,18 @@ public class ConversationActivity extends XmppActivity implements
 	@Override
 	public boolean onCreateOptionsMenu(Menu menu) {
 		getMenuInflater().inflate(R.menu.conversations, menu);
-		MenuItem menuSecure = menu.findItem(R.id.action_security);
-		MenuItem menuArchive = menu.findItem(R.id.action_archive);
-		MenuItem menuMucDetails = menu.findItem(R.id.action_muc_details);
-		MenuItem menuContactDetails = menu
-				.findItem(R.id.action_contact_details);
-		MenuItem menuAttach = menu.findItem(R.id.action_attach_file);
-		MenuItem menuClearHistory = menu.findItem(R.id.action_clear_history);
-		MenuItem menuAdd = menu.findItem(R.id.action_add);
-		MenuItem menuInviteContact = menu.findItem(R.id.action_invite);
-		MenuItem menuMute = menu.findItem(R.id.action_mute);
-		MenuItem menuUnmute = menu.findItem(R.id.action_unmute);
+		final MenuItem menuSecure = menu.findItem(R.id.action_security);
+		final MenuItem menuArchive = menu.findItem(R.id.action_archive);
+		final MenuItem menuMucDetails = menu.findItem(R.id.action_muc_details);
+		final MenuItem menuContactDetails = menu.findItem(R.id.action_contact_details);
+		final MenuItem menuAttach = menu.findItem(R.id.action_attach_file);
+		final MenuItem menuClearHistory = menu.findItem(R.id.action_clear_history);
+		final MenuItem menuAdd = menu.findItem(R.id.action_add);
+		final MenuItem menuInviteContact = menu.findItem(R.id.action_invite);
+		final MenuItem menuMute = menu.findItem(R.id.action_mute);
+		final MenuItem menuUnmute = menu.findItem(R.id.action_unmute);
+		final MenuItem menuBlock = menu.findItem(R.id.action_block);
+		final MenuItem menuUnblock = menu.findItem(R.id.action_unblock);
 
 		if (isConversationsOverviewVisable()
 				&& isConversationsOverviewHideable()) {
@@ -292,19 +294,32 @@ public class ConversationActivity extends XmppActivity implements
 			menuClearHistory.setVisible(false);
 			menuMute.setVisible(false);
 			menuUnmute.setVisible(false);
+			menuBlock.setVisible(false);
+			menuUnblock.setVisible(false);
 		} else {
 			menuAdd.setVisible(!isConversationsOverviewHideable());
 			if (this.getSelectedConversation() != null) {
 				if (this.getSelectedConversation().getLatestMessage()
 						.getEncryption() != Message.ENCRYPTION_NONE) {
 					menuSecure.setIcon(R.drawable.ic_action_secure);
-				}
+						}
 				if (this.getSelectedConversation().getMode() == Conversation.MODE_MULTI) {
 					menuContactDetails.setVisible(false);
 					menuAttach.setVisible(false);
+					menuBlock.setVisible(false);
+					menuUnblock.setVisible(false);
 				} else {
 					menuMucDetails.setVisible(false);
 					menuInviteContact.setTitle(R.string.conference_with);
+					if (this.getSelectedConversation().isBlocked()) {
+						menuBlock.setVisible(false);
+					} else {
+						menuUnblock.setVisible(false);
+					}
+					if (!this.getSelectedConversation().getAccount().getXmppConnection().getFeatures().blocking()) {
+						menuBlock.setVisible(false);
+						menuUnblock.setVisible(false);
+					}
 				}
 				if (this.getSelectedConversation().isMuted()) {
 					menuMute.setVisible(false);
@@ -323,7 +338,7 @@ public class ConversationActivity extends XmppActivity implements
 			public void onPresenceSelected() {
 				if (attachmentChoice == ATTACHMENT_CHOICE_TAKE_PHOTO) {
 					mPendingImageUri = xmppConnectionService.getFileBackend()
-							.getTakePhotoUri();
+						.getTakePhotoUri();
 					Intent takePictureIntent = new Intent(
 							MediaStore.ACTION_IMAGE_CAPTURE);
 					takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT,
@@ -364,7 +379,7 @@ public class ConversationActivity extends XmppActivity implements
 
 								@Override
 								public void userInputRequried(PendingIntent pi,
-															  Contact contact) {
+										Contact contact) {
 									ConversationActivity.this.runIntent(pi,
 											attachmentChoice);
 								}
@@ -381,18 +396,18 @@ public class ConversationActivity extends XmppActivity implements
 							});
 				} else {
 					final ConversationFragment fragment = (ConversationFragment) getFragmentManager()
-							.findFragmentByTag("conversation");
+						.findFragmentByTag("conversation");
 					if (fragment != null) {
 						fragment.showNoPGPKeyDialog(false,
 								new OnClickListener() {
 
 									@Override
 									public void onClick(DialogInterface dialog,
-														int which) {
+											int which) {
 										conversation
-												.setNextEncryption(Message.ENCRYPTION_NONE);
+											.setNextEncryption(Message.ENCRYPTION_NONE);
 										xmppConnectionService.databaseBackend
-												.updateConversation(conversation);
+											.updateConversation(conversation);
 										selectPresenceToAttachFile(attachmentChoice);
 									}
 								});
@@ -402,7 +417,7 @@ public class ConversationActivity extends XmppActivity implements
 				showInstallPgpDialog();
 			}
 		} else if (getSelectedConversation().getNextEncryption(
-				forceEncryption()) == Message.ENCRYPTION_NONE) {
+					forceEncryption()) == Message.ENCRYPTION_NONE) {
 			selectPresenceToAttachFile(attachmentChoice);
 		} else {
 			selectPresenceToAttachFile(attachmentChoice);
@@ -410,7 +425,7 @@ public class ConversationActivity extends XmppActivity implements
 	}
 
 	@Override
-	public boolean onOptionsItemSelected(MenuItem item) {
+	public boolean onOptionsItemSelected(final MenuItem item) {
 		if (item.getItemId() == android.R.id.home) {
 			showConversationsOverview();
 			return true;
@@ -455,6 +470,12 @@ public class ConversationActivity extends XmppActivity implements
 				case R.id.action_unmute:
 					unmuteConversation(getSelectedConversation());
 					break;
+				case R.id.action_block:
+					BlockContactDialog.show(this, xmppConnectionService, getSelectedConversation());
+					break;
+				case R.id.action_unblock:
+					BlockContactDialog.show(this, xmppConnectionService, getSelectedConversation());
+					break;
 				default:
 					break;
 			}
@@ -483,7 +504,7 @@ public class ConversationActivity extends XmppActivity implements
 		View dialogView = getLayoutInflater().inflate(
 				R.layout.dialog_clear_history, null);
 		final CheckBox endConversationCheckBox = (CheckBox) dialogView
-				.findViewById(R.id.end_conversation_checkbox);
+			.findViewById(R.id.end_conversation_checkbox);
 		builder.setView(dialogView);
 		builder.setNegativeButton(getString(R.string.cancel), null);
 		builder.setPositiveButton(getString(R.string.delete_messages),
@@ -511,24 +532,24 @@ public class ConversationActivity extends XmppActivity implements
 		PopupMenu attachFilePopup = new PopupMenu(this, menuAttachFile);
 		attachFilePopup.inflate(R.menu.attachment_choices);
 		attachFilePopup
-				.setOnMenuItemClickListener(new OnMenuItemClickListener() {
+			.setOnMenuItemClickListener(new OnMenuItemClickListener() {
 
-					@Override
-					public boolean onMenuItemClick(MenuItem item) {
-						switch (item.getItemId()) {
-							case R.id.attach_choose_picture:
-								attachFile(ATTACHMENT_CHOICE_CHOOSE_IMAGE);
-								break;
-							case R.id.attach_take_picture:
-								attachFile(ATTACHMENT_CHOICE_TAKE_PHOTO);
-								break;
-							case R.id.attach_record_voice:
-								attachFile(ATTACHMENT_CHOICE_CHOOSE_FILE);
-								break;
-						}
-						return false;
+				@Override
+				public boolean onMenuItemClick(MenuItem item) {
+					switch (item.getItemId()) {
+						case R.id.attach_choose_picture:
+							attachFile(ATTACHMENT_CHOICE_CHOOSE_IMAGE);
+							break;
+						case R.id.attach_take_picture:
+							attachFile(ATTACHMENT_CHOICE_TAKE_PHOTO);
+							break;
+						case R.id.attach_record_voice:
+							attachFile(ATTACHMENT_CHOICE_CHOOSE_FILE);
+							break;
 					}
-				});
+					return false;
+				}
+			});
 		attachFilePopup.show();
 	}
 
@@ -539,7 +560,7 @@ public class ConversationActivity extends XmppActivity implements
 		}
 		PopupMenu popup = new PopupMenu(this, menuItemView);
 		final ConversationFragment fragment = (ConversationFragment) getFragmentManager()
-				.findFragmentByTag("conversation");
+			.findFragmentByTag("conversation");
 		if (fragment != null) {
 			popup.setOnMenuItemClickListener(new OnMenuItemClickListener() {
 
@@ -559,7 +580,7 @@ public class ConversationActivity extends XmppActivity implements
 								if (conversation.getAccount().getKeys()
 										.has("pgp_signature")) {
 									conversation
-											.setNextEncryption(Message.ENCRYPTION_PGP);
+										.setNextEncryption(Message.ENCRYPTION_PGP);
 									item.setChecked(true);
 								} else {
 									announcePgp(conversation.getAccount(),
@@ -574,7 +595,7 @@ public class ConversationActivity extends XmppActivity implements
 							break;
 					}
 					xmppConnectionService.databaseBackend
-							.updateConversation(conversation);
+						.updateConversation(conversation);
 					fragment.updateChatMsgHint();
 					return true;
 				}
@@ -599,11 +620,11 @@ public class ConversationActivity extends XmppActivity implements
 					break;
 				case Message.ENCRYPTION_PGP:
 					popup.getMenu().findItem(R.id.encryption_choice_pgp)
-							.setChecked(true);
+						.setChecked(true);
 					break;
 				default:
 					popup.getMenu().findItem(R.id.encryption_choice_none)
-							.setChecked(true);
+						.setChecked(true);
 					break;
 			}
 			popup.show();
@@ -619,17 +640,17 @@ public class ConversationActivity extends XmppActivity implements
 				new OnClickListener() {
 
 					@Override
-					public void onClick(DialogInterface dialog, int which) {
-						long till;
+					public void onClick(final DialogInterface dialog, final int which) {
+						final long till;
 						if (durations[which] == -1) {
 							till = Long.MAX_VALUE;
 						} else {
 							till = SystemClock.elapsedRealtime()
-									+ (durations[which] * 1000);
+								+ (durations[which] * 1000);
 						}
 						conversation.setMutedTill(till);
 						ConversationActivity.this.xmppConnectionService.databaseBackend
-								.updateConversation(conversation);
+							.updateConversation(conversation);
 						updateConversationList();
 						ConversationActivity.this.mConversationFragment.updateMessages();
 						invalidateOptionsMenu();
@@ -763,11 +784,11 @@ public class ConversationActivity extends XmppActivity implements
 	}
 
 	private void selectConversationByUuid(String uuid) {
-        for (Conversation aConversationList : conversationList) {
-            if (aConversationList.getUuid().equals(uuid)) {
-                setSelectedConversation(aConversationList);
-            }
-        }
+		for (Conversation aConversationList : conversationList) {
+			if (aConversationList.getUuid().equals(uuid)) {
+				setSelectedConversation(aConversationList);
+			}
+		}
 	}
 
 	@Override
@@ -778,7 +799,7 @@ public class ConversationActivity extends XmppActivity implements
 
 	@Override
 	protected void onActivityResult(int requestCode, int resultCode,
-									final Intent data) {
+			final Intent data) {
 		super.onActivityResult(requestCode, resultCode, data);
 		if (resultCode == RESULT_OK) {
 			if (requestCode == REQUEST_DECRYPT_PGP) {
@@ -859,7 +880,7 @@ public class ConversationActivity extends XmppActivity implements
 
 					@Override
 					public void userInputRequried(PendingIntent pi,
-												  Message object) {
+							Message object) {
 						hidePrepareFileToast();
 						ConversationActivity.this.runIntent(pi,
 								ConversationActivity.REQUEST_SEND_PGP_IMAGE);
@@ -892,7 +913,7 @@ public class ConversationActivity extends XmppActivity implements
 
 	public void updateConversationList() {
 		xmppConnectionService
-				.populateWithOrderedConversations(conversationList);
+			.populateWithOrderedConversations(conversationList);
 		listAdapter.notifyDataSetChanged();
 	}
 
@@ -910,7 +931,7 @@ public class ConversationActivity extends XmppActivity implements
 
 					@Override
 					public void userInputRequried(PendingIntent pi,
-												  Message message) {
+							Message message) {
 						ConversationActivity.this.runIntent(pi,
 								ConversationActivity.REQUEST_SEND_MESSAGE);
 					}
@@ -962,7 +983,7 @@ public class ConversationActivity extends XmppActivity implements
 				updateConversationList();
 				if (conversationList.size() == 0) {
 					startActivity(new Intent(getApplicationContext(),
-							StartConversationActivity.class));
+								StartConversationActivity.class));
 					finish();
 				}
 				ConversationActivity.this.mConversationFragment.updateMessages();
@@ -975,12 +996,31 @@ public class ConversationActivity extends XmppActivity implements
 	public void onRosterUpdate() {
 		runOnUiThread(new Runnable() {
 
-				@Override
-				public void run() {
-					updateConversationList();
-					ConversationActivity.this.mConversationFragment.updateMessages();
-					updateActionBarTitle();
-				}
-			});
+			@Override
+			public void run() {
+				updateConversationList();
+				ConversationActivity.this.mConversationFragment.updateMessages();
+				updateActionBarTitle();
+			}
+		});
+	}
+
+	@Override
+	public void OnUpdateBlocklist(Status status) {
+		invalidateOptionsMenu();
+		runOnUiThread(new Runnable() {
+			@Override
+			public void run() {
+				ConversationActivity.this.mConversationFragment.updateMessages();
+			}
+		});
+	}
+
+	public void unblockConversation(final Blockable conversation) {
+		xmppConnectionService.sendUnblockRequest(conversation);
+	}
+
+	public void blockConversation(final Blockable conversation) {
+		xmppConnectionService.sendBlockRequest(conversation);
 	}
 }
diff --git a/src/main/java/eu/siacs/conversations/ui/ConversationFragment.java b/src/main/java/eu/siacs/conversations/ui/ConversationFragment.java
index e4c3fa9e..d356c73c 100644
--- a/src/main/java/eu/siacs/conversations/ui/ConversationFragment.java
+++ b/src/main/java/eu/siacs/conversations/ui/ConversationFragment.java
@@ -9,7 +9,6 @@ import android.content.Intent;
 import android.content.IntentSender;
 import android.content.IntentSender.SendIntentException;
 import android.os.Bundle;
-import android.util.Log;
 import android.view.ContextMenu;
 import android.view.ContextMenu.ContextMenuInfo;
 import android.view.Gravity;
@@ -39,7 +38,6 @@ import java.util.List;
 import java.util.NoSuchElementException;
 import java.util.concurrent.ConcurrentLinkedQueue;
 
-import eu.siacs.conversations.Config;
 import eu.siacs.conversations.R;
 import eu.siacs.conversations.crypto.PgpEngine;
 import eu.siacs.conversations.entities.Account;
@@ -118,7 +116,7 @@ public class ConversationFragment extends Fragment {
 
 		@Override
 		public void onScroll(AbsListView view, int firstVisibleItem,
-							 int visibleItemCount, int totalItemCount) {
+				int visibleItemCount, int totalItemCount) {
 			synchronized (ConversationFragment.this.messageList) {
 				if (firstVisibleItem < 5 && messagesLoaded && messageList.size() > 0) {
 					long timestamp = ConversationFragment.this.messageList.get(0).getTimeSent();
@@ -223,7 +221,7 @@ public class ConversationFragment extends Fragment {
 		public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
 			if (actionId == EditorInfo.IME_ACTION_SEND) {
 				InputMethodManager imm = (InputMethodManager) v.getContext()
-						.getSystemService(Context.INPUT_METHOD_SERVICE);
+					.getSystemService(Context.INPUT_METHOD_SERVICE);
 				imm.hideSoftInputFromWindow(v.getWindowToken(), 0);
 				sendMessage();
 				return true;
@@ -266,7 +264,7 @@ public class ConversationFragment extends Fragment {
 		}
 		Message message = new Message(conversation, mEditMessage.getText()
 				.toString(), conversation.getNextEncryption(activity
-				.forceEncryption()));
+					.forceEncryption()));
 		if (conversation.getMode() == Conversation.MODE_MULTI) {
 			if (conversation.getNextCounterpart() != null) {
 				message.setCounterpart(conversation.getNextCounterpart());
@@ -287,13 +285,13 @@ public class ConversationFragment extends Fragment {
 		if (conversation.getMode() == Conversation.MODE_MULTI
 				&& conversation.getNextCounterpart() != null) {
 			this.mEditMessage.setHint(getString(
-					R.string.send_private_message_to,
-					conversation.getNextCounterpart().getResourcepart()));
+						R.string.send_private_message_to,
+						conversation.getNextCounterpart().getResourcepart()));
 		} else {
 			switch (conversation.getNextEncryption(activity.forceEncryption())) {
 				case Message.ENCRYPTION_NONE:
 					mEditMessage
-							.setHint(getString(R.string.send_plain_text_message));
+						.setHint(getString(R.string.send_plain_text_message));
 					break;
 				case Message.ENCRYPTION_OTR:
 					mEditMessage.setHint(getString(R.string.send_otr_message));
@@ -309,7 +307,7 @@ public class ConversationFragment extends Fragment {
 
 	@Override
 	public View onCreateView(final LayoutInflater inflater,
-							 ViewGroup container, Bundle savedInstanceState) {
+			ViewGroup container, Bundle savedInstanceState) {
 		final View view = inflater.inflate(R.layout.fragment_conversation,
 				container, false);
 		mEditMessage = (EditMessage) view.findViewById(R.id.textinput);
@@ -342,49 +340,49 @@ public class ConversationFragment extends Fragment {
 		messageListAdapter = new MessageAdapter((ConversationActivity) getActivity(), this.messageList);
 		messageListAdapter.setOnContactPictureClicked(new OnContactPictureClicked() {
 
-					@Override
-					public void onContactPictureClicked(Message message) {
-						if (message.getStatus() <= Message.STATUS_RECEIVED) {
-							if (message.getConversation().getMode() == Conversation.MODE_MULTI) {
-								if (message.getCounterpart() != null) {
-									if (!message.getCounterpart().isBareJid()) {
-										highlightInConference(message.getCounterpart().getResourcepart());
-									} else {
-										highlightInConference(message.getCounterpart().toString());
-									}
-								}
+			@Override
+			public void onContactPictureClicked(Message message) {
+				if (message.getStatus() <= Message.STATUS_RECEIVED) {
+					if (message.getConversation().getMode() == Conversation.MODE_MULTI) {
+						if (message.getCounterpart() != null) {
+							if (!message.getCounterpart().isBareJid()) {
+								highlightInConference(message.getCounterpart().getResourcepart());
 							} else {
-								Contact contact = message.getConversation()
-										.getContact();
-								if (contact.showInRoster()) {
-									activity.switchToContactDetails(contact);
-								} else {
-									activity.showAddToRosterDialog(message
-											.getConversation());
-								}
+								highlightInConference(message.getCounterpart().toString());
 							}
+						}
+					} else {
+						Contact contact = message.getConversation()
+							.getContact();
+						if (contact.showInRoster()) {
+							activity.switchToContactDetails(contact);
 						} else {
-							Account account = message.getConversation().getAccount();
-							Intent intent = new Intent(activity, EditAccountActivity.class);
-							intent.putExtra("jid", account.getJid().toBareJid().toString());
-							startActivity(intent);
+							activity.showAddToRosterDialog(message
+									.getConversation());
 						}
 					}
-				});
+				} else {
+					Account account = message.getConversation().getAccount();
+					Intent intent = new Intent(activity, EditAccountActivity.class);
+					intent.putExtra("jid", account.getJid().toBareJid().toString());
+					startActivity(intent);
+				}
+			}
+		});
 		messageListAdapter
-				.setOnContactPictureLongClicked(new OnContactPictureLongClicked() {
+			.setOnContactPictureLongClicked(new OnContactPictureLongClicked() {
 
-					@Override
-					public void onContactPictureLongClicked(Message message) {
-						if (message.getStatus() <= Message.STATUS_RECEIVED) {
-							if (message.getConversation().getMode() == Conversation.MODE_MULTI) {
-								if (message.getCounterpart() != null) {
-									privateMessageWith(message.getCounterpart());
-								}
+				@Override
+				public void onContactPictureLongClicked(Message message) {
+					if (message.getStatus() <= Message.STATUS_RECEIVED) {
+						if (message.getConversation().getMode() == Conversation.MODE_MULTI) {
+							if (message.getCounterpart() != null) {
+								privateMessageWith(message.getCounterpart());
 							}
 						}
 					}
-				});
+				}
+			});
 		messagesView.setAdapter(messageListAdapter);
 
 		registerForContextMenu(messagesView);
@@ -394,7 +392,7 @@ public class ConversationFragment extends Fragment {
 
 	@Override
 	public void onCreateContextMenu(ContextMenu menu, View v,
-									ContextMenuInfo menuInfo) {
+			ContextMenuInfo menuInfo) {
 		synchronized (this.messageList) {
 			super.onCreateContextMenu(menu, v, menuInfo);
 			AdapterView.AdapterContextMenuInfo acmi = (AdapterContextMenuInfo) menuInfo;
@@ -416,28 +414,28 @@ public class ConversationFragment extends Fragment {
 			if (this.selectedMessage.getType() != Message.TYPE_TEXT
 					|| this.selectedMessage.getDownloadable() != null) {
 				copyText.setVisible(false);
-			}
+					}
 			if (this.selectedMessage.getType() != Message.TYPE_IMAGE
 					|| this.selectedMessage.getDownloadable() != null) {
 				shareImage.setVisible(false);
-			}
+					}
 			if (this.selectedMessage.getStatus() != Message.STATUS_SEND_FAILED) {
 				sendAgain.setVisible(false);
 			}
 			if ((this.selectedMessage.getType() != Message.TYPE_IMAGE && this.selectedMessage
-					.getDownloadable() == null)
+						.getDownloadable() == null)
 					|| this.selectedMessage.getImageParams().url == null) {
 				copyUrl.setVisible(false);
-			}
+					}
 			if (this.selectedMessage.getType() != Message.TYPE_TEXT
 					|| this.selectedMessage.getDownloadable() != null
 					|| !this.selectedMessage.bodyContainsDownloadable()) {
 				downloadImage.setVisible(false);
-			}
+					}
 			if (this.selectedMessage.getDownloadable() == null
 					|| this.selectedMessage.getDownloadable() instanceof DownloadablePlaceholder) {
 				cancelTransmission.setVisible(false);
-			}
+					}
 		}
 	}
 
@@ -472,16 +470,16 @@ public class ConversationFragment extends Fragment {
 		shareIntent.setAction(Intent.ACTION_SEND);
 		shareIntent.putExtra(Intent.EXTRA_STREAM,
 				activity.xmppConnectionService.getFileBackend()
-						.getJingleFileUri(message));
+				.getJingleFileUri(message));
 		shareIntent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
 		shareIntent.setType("image/webp");
 		activity.startActivity(Intent.createChooser(shareIntent,
-				getText(R.string.share_with)));
+					getText(R.string.share_with)));
 	}
 
 	private void copyText(Message message) {
 		if (activity.copyTextToClipboard(message.getMergedBody(),
-				R.string.message_text)) {
+					R.string.message_text)) {
 			Toast.makeText(activity, R.string.message_copied_to_clipboard,
 					Toast.LENGTH_SHORT).show();
 		}
@@ -501,15 +499,15 @@ public class ConversationFragment extends Fragment {
 
 	private void copyUrl(Message message) {
 		if (activity.copyTextToClipboard(
-				message.getImageParams().url.toString(), R.string.image_url)) {
+					message.getImageParams().url.toString(), R.string.image_url)) {
 			Toast.makeText(activity, R.string.url_copied_to_clipboard,
 					Toast.LENGTH_SHORT).show();
-		}
+					}
 	}
 
 	private void downloadImage(Message message) {
 		activity.xmppConnectionService.getHttpConnectionManager()
-				.createNewConnection(message);
+			.createNewConnection(message);
 	}
 
 	private void cancelTransmission(Message message) {
@@ -531,9 +529,9 @@ public class ConversationFragment extends Fragment {
 			mEditMessage.getText().insert(0, nick + ": ");
 		} else {
 			if (mEditMessage.getText().charAt(
-					mEditMessage.getSelectionStart() - 1) != ' ') {
+						mEditMessage.getSelectionStart() - 1) != ' ') {
 				nick = " " + nick;
-			}
+						}
 			mEditMessage.getText().insert(mEditMessage.getSelectionStart(),
 					nick + " ");
 		}
@@ -583,12 +581,30 @@ public class ConversationFragment extends Fragment {
 			final ConversationActivity activity = (ConversationActivity) getActivity();
 			if (this.conversation != null) {
 				final Contact contact = this.conversation.getContact();
-				if (this.conversation.isMuted()) {
+				if (this.conversation.isBlocked()) {
+					showSnackbar(R.string.contact_blocked, R.string.unblock,
+							new OnClickListener() {
+								@Override
+								public void onClick(final View v) {
+									v.post(new Runnable() {
+										@Override
+										public void run() {
+											v.setVisibility(View.INVISIBLE);
+										}
+									});
+									if (conversation.isDomainBlocked()) {
+										BlockContactDialog.show(getActivity(), ((ConversationActivity) getActivity()).xmppConnectionService, conversation);
+									} else {
+										((ConversationActivity) getActivity()).unblockConversation(conversation);
+									}
+								}
+							});
+				} else if (this.conversation.isMuted()) {
 					showSnackbar(R.string.notifications_disabled, R.string.enable,
 							new OnClickListener() {
 
 								@Override
-								public void onClick(View v) {
+								public void onClick(final View v) {
 									activity.unmuteConversation(conversation);
 								}
 							});
@@ -601,7 +617,7 @@ public class ConversationFragment extends Fragment {
 								@Override
 								public void onClick(View v) {
 									activity.xmppConnectionService
-											.createContact(contact);
+										.createContact(contact);
 									activity.switchToContactDetails(contact);
 								}
 							});
@@ -638,17 +654,17 @@ public class ConversationFragment extends Fragment {
 						default:
 							break;
 					}
-				}
+						}
 				conversation.populateWithMessages(ConversationFragment.this.messageList);
 				for (Message message : this.messageList) {
 					if (message.getEncryption() == Message.ENCRYPTION_PGP
 							&& (message.getStatus() == Message.STATUS_RECEIVED || message
-							.getStatus() >= Message.STATUS_SEND)
+								.getStatus() >= Message.STATUS_SEND)
 							&& message.getDownloadable() == null) {
 						if (!mEncryptedMessages.contains(message)) {
 							mEncryptedMessages.add(message);
 						}
-					}
+							}
 				}
 				decryptNext();
 				updateStatusMessages();
@@ -720,44 +736,44 @@ public class ConversationFragment extends Fragment {
 				switch (c.getContact().getMostAvailableStatus()) {
 					case Presences.CHAT:
 						this.mSendButton
-								.setImageResource(R.drawable.ic_action_send_now_online);
+							.setImageResource(R.drawable.ic_action_send_now_online);
 						break;
 					case Presences.ONLINE:
 						this.mSendButton
-								.setImageResource(R.drawable.ic_action_send_now_online);
+							.setImageResource(R.drawable.ic_action_send_now_online);
 						break;
 					case Presences.AWAY:
 						this.mSendButton
-								.setImageResource(R.drawable.ic_action_send_now_away);
+							.setImageResource(R.drawable.ic_action_send_now_away);
 						break;
 					case Presences.XA:
 						this.mSendButton
-								.setImageResource(R.drawable.ic_action_send_now_away);
+							.setImageResource(R.drawable.ic_action_send_now_away);
 						break;
 					case Presences.DND:
 						this.mSendButton
-								.setImageResource(R.drawable.ic_action_send_now_dnd);
+							.setImageResource(R.drawable.ic_action_send_now_dnd);
 						break;
 					default:
 						this.mSendButton
-								.setImageResource(R.drawable.ic_action_send_now_offline);
+							.setImageResource(R.drawable.ic_action_send_now_offline);
 						break;
 				}
 			} else if (c.getMode() == Conversation.MODE_MULTI) {
 				if (c.getMucOptions().online()) {
 					this.mSendButton
-							.setImageResource(R.drawable.ic_action_send_now_online);
+						.setImageResource(R.drawable.ic_action_send_now_online);
 				} else {
 					this.mSendButton
-							.setImageResource(R.drawable.ic_action_send_now_offline);
+						.setImageResource(R.drawable.ic_action_send_now_offline);
 				}
 			} else {
 				this.mSendButton
-						.setImageResource(R.drawable.ic_action_send_now_offline);
+					.setImageResource(R.drawable.ic_action_send_now_offline);
 			}
 		} else {
 			this.mSendButton
-					.setImageResource(R.drawable.ic_action_send_now_offline);
+				.setImageResource(R.drawable.ic_action_send_now_offline);
 		}
 	}
 
@@ -784,15 +800,16 @@ public class ConversationFragment extends Fragment {
 		} else if (conversation.hasValidOtrSession() && (conversation.getOtrSession().getSessionStatus() == SessionStatus.ENCRYPTED)
 				&& (!conversation.isOtrFingerprintVerified())) {
 			showSnackbar(R.string.unknown_otr_fingerprint, R.string.verify, clickToVerify);
-		}
+				}
 	}
 
-	protected void showSnackbar(int message, int action,
-								OnClickListener clickListener) {
+	protected void showSnackbar(final int message, final int action,
+			final OnClickListener clickListener) {
 		snackbar.setVisibility(View.VISIBLE);
 		snackbar.setOnClickListener(null);
 		snackbarMessage.setText(message);
 		snackbarMessage.setOnClickListener(null);
+		snackbarAction.setVisibility(View.VISIBLE);
 		snackbarAction.setText(action);
 		snackbarAction.setOnClickListener(clickListener);
 	}
@@ -819,7 +836,7 @@ public class ConversationFragment extends Fragment {
 
 								@Override
 								public void userInputRequried(PendingIntent pi,
-															  Contact contact) {
+										Contact contact) {
 									activity.runIntent(
 											pi,
 											ConversationActivity.REQUEST_ENCRYPT_MESSAGE);
@@ -843,11 +860,11 @@ public class ConversationFragment extends Fragment {
 
 								@Override
 								public void onClick(DialogInterface dialog,
-													int which) {
+										int which) {
 									conversation
-											.setNextEncryption(Message.ENCRYPTION_NONE);
+										.setNextEncryption(Message.ENCRYPTION_NONE);
 									xmppService.databaseBackend
-											.updateConversation(conversation);
+										.updateConversation(conversation);
 									message.setEncryption(Message.ENCRYPTION_NONE);
 									xmppService.sendMessage(message);
 									messageSent();
@@ -858,9 +875,9 @@ public class ConversationFragment extends Fragment {
 				if (conversation.getMucOptions().pgpKeysInUse()) {
 					if (!conversation.getMucOptions().everybodyHasKeys()) {
 						Toast warning = Toast
-								.makeText(getActivity(),
-										R.string.missing_public_keys,
-										Toast.LENGTH_LONG);
+							.makeText(getActivity(),
+									R.string.missing_public_keys,
+									Toast.LENGTH_LONG);
 						warning.setGravity(Gravity.CENTER_VERTICAL, 0, 0);
 						warning.show();
 					}
@@ -872,12 +889,12 @@ public class ConversationFragment extends Fragment {
 
 								@Override
 								public void onClick(DialogInterface dialog,
-													int which) {
+										int which) {
 									conversation
-											.setNextEncryption(Message.ENCRYPTION_NONE);
+										.setNextEncryption(Message.ENCRYPTION_NONE);
 									message.setEncryption(Message.ENCRYPTION_NONE);
 									xmppService.databaseBackend
-											.updateConversation(conversation);
+										.updateConversation(conversation);
 									xmppService.sendMessage(message);
 									messageSent();
 								}
@@ -890,7 +907,7 @@ public class ConversationFragment extends Fragment {
 	}
 
 	public void showNoPGPKeyDialog(boolean plural,
-								   DialogInterface.OnClickListener listener) {
+			DialogInterface.OnClickListener listener) {
 		AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
 		builder.setIconAttribute(android.R.attr.alertDialogIcon);
 		if (plural) {
diff --git a/src/main/java/eu/siacs/conversations/ui/EditAccountActivity.java b/src/main/java/eu/siacs/conversations/ui/EditAccountActivity.java
index 8fad66cf..47fe5964 100644
--- a/src/main/java/eu/siacs/conversations/ui/EditAccountActivity.java
+++ b/src/main/java/eu/siacs/conversations/ui/EditAccountActivity.java
@@ -67,7 +67,7 @@ public class EditAccountActivity extends XmppActivity implements OnAccountUpdate
 				mAccount.setOption(Account.OPTION_DISABLED, false);
 				xmppConnectionService.updateAccount(mAccount);
 				return;
-			}
+					}
 			if (!Validator.isValidJid(mAccountJid.getText().toString())) {
 				mAccountJid.setError(getString(R.string.invalid_jid));
 				mAccountJid.requestFocus();
@@ -87,32 +87,32 @@ public class EditAccountActivity extends XmppActivity implements OnAccountUpdate
 			if (registerNewAccount) {
 				if (!password.equals(passwordConfirm)) {
 					mPasswordConfirm
-							.setError(getString(R.string.passwords_do_not_match));
+						.setError(getString(R.string.passwords_do_not_match));
 					mPasswordConfirm.requestFocus();
 					return;
 				}
 			}
 			if (mAccount != null) {
 				mAccount.setPassword(password);
-                try {
-                    mAccount.setUsername(jid.hasLocalpart() ? jid.getLocalpart() : "");
-                    mAccount.setServer(jid.getDomainpart());
-                } catch (final InvalidJidException ignored) {
-                }
+				try {
+					mAccount.setUsername(jid.hasLocalpart() ? jid.getLocalpart() : "");
+					mAccount.setServer(jid.getDomainpart());
+				} catch (final InvalidJidException ignored) {
+				}
 				mAccount.setOption(Account.OPTION_REGISTER, registerNewAccount);
 				xmppConnectionService.updateAccount(mAccount);
 			} else {
-                try {
-                    if (xmppConnectionService.findAccountByJid(Jid.fromString(mAccountJid.getText().toString())) != null) {
-                        mAccountJid
-                                .setError(getString(R.string.account_already_exists));
-                        mAccountJid.requestFocus();
-                        return;
-                    }
-                } catch (InvalidJidException e) {
-                    return;
-                }
-                mAccount = new Account(jid.toBareJid(), password);
+				try {
+					if (xmppConnectionService.findAccountByJid(Jid.fromString(mAccountJid.getText().toString())) != null) {
+						mAccountJid
+							.setError(getString(R.string.account_already_exists));
+						mAccountJid.requestFocus();
+						return;
+					}
+				} catch (InvalidJidException e) {
+					return;
+				}
+				mAccount = new Account(jid.toBareJid(), password);
 				mAccount.setOption(Account.OPTION_USETLS, true);
 				mAccount.setOption(Account.OPTION_USECOMPRESSION, true);
 				mAccount.setOption(Account.OPTION_REGISTER, registerNewAccount);
@@ -134,34 +134,34 @@ public class EditAccountActivity extends XmppActivity implements OnAccountUpdate
 			finish();
 		}
 	};
-		@Override
-		public void onAccountUpdate() {
-			runOnUiThread(new Runnable() {
+	@Override
+	public void onAccountUpdate() {
+		runOnUiThread(new Runnable() {
 
-				@Override
-				public void run() {
-					if (mAccount != null
-							&& mAccount.getStatus() != Account.State.ONLINE
-							&& mFetchingAvatar) {
-						startActivity(new Intent(getApplicationContext(),
+			@Override
+			public void run() {
+				if (mAccount != null
+						&& mAccount.getStatus() != Account.State.ONLINE
+						&& mFetchingAvatar) {
+					startActivity(new Intent(getApplicationContext(),
 								ManageAccountActivity.class));
-						finish();
-					} else if (jidToEdit == null && mAccount != null
-							&& mAccount.getStatus() == Account.State.ONLINE) {
-						if (!mFetchingAvatar) {
-							mFetchingAvatar = true;
-							xmppConnectionService.checkForAvatar(mAccount,
-									mAvatarFetchCallback);
-						}
-					} else {
-						updateSaveButton();
-					}
-					if (mAccount != null) {
-						updateAccountInformation();
+					finish();
+				} else if (jidToEdit == null && mAccount != null
+						&& mAccount.getStatus() == Account.State.ONLINE) {
+					if (!mFetchingAvatar) {
+						mFetchingAvatar = true;
+						xmppConnectionService.checkForAvatar(mAccount,
+								mAvatarFetchCallback);
 					}
+				} else {
+					updateSaveButton();
 				}
-			});
-		}
+				if (mAccount != null) {
+					updateAccountInformation();
+				}
+			}
+		});
+	}
 	private UiCallback<Avatar> mAvatarFetchCallback = new UiCallback<Avatar>() {
 
 		@Override
@@ -179,17 +179,17 @@ public class EditAccountActivity extends XmppActivity implements OnAccountUpdate
 			finishInitialSetup(avatar);
 		}
 	};
-    private TextWatcher mTextWatcher = new TextWatcher() {
+	private TextWatcher mTextWatcher = new TextWatcher() {
 
 		@Override
 		public void onTextChanged(CharSequence s, int start, int before,
-								  int count) {
+				int count) {
 			updateSaveButton();
 		}
 
 		@Override
 		public void beforeTextChanged(CharSequence s, int start, int count,
-									  int after) {
+				int after) {
 
 		}
 
@@ -264,9 +264,9 @@ public class EditAccountActivity extends XmppActivity implements OnAccountUpdate
 
 	protected boolean accountInfoEdited() {
 		return (!this.mAccount.getJid().toBareJid().equals(
-				this.mAccountJid.getText().toString()))
-				|| (!this.mAccount.getPassword().equals(
-				this.mPassword.getText().toString()));
+					this.mAccountJid.getText().toString()))
+			|| (!this.mAccount.getPassword().equals(
+						this.mPassword.getText().toString()));
 	}
 
 	@Override
@@ -303,28 +303,32 @@ public class EditAccountActivity extends XmppActivity implements OnAccountUpdate
 		this.mSaveButton.setOnClickListener(this.mSaveButtonClickListener);
 		this.mCancelButton.setOnClickListener(this.mCancelButtonClickListener);
 		this.mRegisterNew
-				.setOnCheckedChangeListener(new OnCheckedChangeListener() {
-
-					@Override
-					public void onCheckedChanged(CompoundButton buttonView,
-												 boolean isChecked) {
-						if (isChecked) {
-							mPasswordConfirm.setVisibility(View.VISIBLE);
-						} else {
-							mPasswordConfirm.setVisibility(View.GONE);
-						}
-						updateSaveButton();
+			.setOnCheckedChangeListener(new OnCheckedChangeListener() {
+
+				@Override
+				public void onCheckedChanged(CompoundButton buttonView,
+						boolean isChecked) {
+					if (isChecked) {
+						mPasswordConfirm.setVisibility(View.VISIBLE);
+					} else {
+						mPasswordConfirm.setVisibility(View.GONE);
 					}
-				});
+					updateSaveButton();
+				}
+			});
 	}
 
 	@Override
-	public boolean onCreateOptionsMenu(Menu menu) {
+	public boolean onCreateOptionsMenu(final Menu menu) {
 		super.onCreateOptionsMenu(menu);
 		getMenuInflater().inflate(R.menu.editaccount, menu);
-		MenuItem showQrCode = menu.findItem(R.id.action_show_qr_code);
+		final MenuItem showQrCode = menu.findItem(R.id.action_show_qr_code);
+		final MenuItem showBlocklist = menu.findItem(R.id.action_show_block_list);
 		if (mAccount == null) {
 			showQrCode.setVisible(false);
+			showBlocklist.setVisible(false);
+		} else if (!mAccount.getXmppConnection().getFeatures().blocking()) {
+			showBlocklist.setVisible(false);
 		}
 		return true;
 	}
@@ -333,32 +337,38 @@ public class EditAccountActivity extends XmppActivity implements OnAccountUpdate
 	protected void onStart() {
 		super.onStart();
 		if (getIntent() != null) {
-            try {
-                this.jidToEdit = Jid.fromString(getIntent().getStringExtra("jid"));
-            } catch (final InvalidJidException | NullPointerException ignored) {
-                this.jidToEdit = null;
-            }
-            if (this.jidToEdit != null) {
+			try {
+				this.jidToEdit = Jid.fromString(getIntent().getStringExtra("jid"));
+			} catch (final InvalidJidException | NullPointerException ignored) {
+				this.jidToEdit = null;
+			}
+			if (this.jidToEdit != null) {
 				this.mRegisterNew.setVisibility(View.GONE);
-				getActionBar().setTitle(getString(R.string.account_details));
+				if (getActionBar() != null) {
+					getActionBar().setTitle(getString(R.string.account_details));
+				}
 			} else {
 				this.mAvatar.setVisibility(View.GONE);
-				getActionBar().setTitle(R.string.action_add_account);
+				if (getActionBar() != null) {
+					getActionBar().setTitle(R.string.action_add_account);
+				}
 			}
 		}
 	}
 
 	@Override
 	protected void onBackendConnected() {
-        KnownHostsAdapter mKnownHostsAdapter = new KnownHostsAdapter(this,
-                android.R.layout.simple_list_item_1,
-                xmppConnectionService.getKnownHosts());
+		final KnownHostsAdapter mKnownHostsAdapter = new KnownHostsAdapter(this,
+				android.R.layout.simple_list_item_1,
+				xmppConnectionService.getKnownHosts());
 		if (this.jidToEdit != null) {
 			this.mAccount = xmppConnectionService.findAccountByJid(jidToEdit);
 			updateAccountInformation();
 		} else if (this.xmppConnectionService.getAccounts().size() == 0) {
-			getActionBar().setDisplayHomeAsUpEnabled(false);
-			getActionBar().setDisplayShowHomeEnabled(false);
+			if (getActionBar() != null) {
+				getActionBar().setDisplayHomeAsUpEnabled(false);
+				getActionBar().setDisplayShowHomeEnabled(false);
+			}
 			this.mCancelButton.setEnabled(false);
 			this.mCancelButton.setTextColor(getSecondaryTextColor());
 		}
@@ -366,6 +376,18 @@ public class EditAccountActivity extends XmppActivity implements OnAccountUpdate
 		updateSaveButton();
 	}
 
+	@Override
+	public boolean onOptionsItemSelected(final MenuItem item) {
+		switch (item.getItemId()) {
+			case R.id.action_show_block_list:
+				final Intent intent = new Intent(this, BlocklistActivity.class);
+				intent.putExtra("account", mAccount.getJid().toString());
+				startActivity(intent);
+				break;
+		}
+		return super.onOptionsItemSelected(item);
+	}
+
 	private void updateAccountInformation() {
 		this.mAccountJid.setText(this.mAccount.getJid().toBareJid().toString());
 		this.mPassword.setText(this.mAccount.getPassword());
@@ -385,14 +407,14 @@ public class EditAccountActivity extends XmppActivity implements OnAccountUpdate
 				&& !this.mFetchingAvatar) {
 			this.mStats.setVisibility(View.VISIBLE);
 			this.mSessionEst.setText(UIHelper.readableTimeDifferenceFull(
-					getApplicationContext(), this.mAccount.getXmppConnection()
-							.getLastSessionEstablished()));
-			Features features = this.mAccount.getXmppConnection().getFeatures();
+						getApplicationContext(), this.mAccount.getXmppConnection()
+						.getLastSessionEstablished()));
+			final Features features = this.mAccount.getXmppConnection().getFeatures();
 			if (features.carbons()) {
 				this.mServerInfoCarbons.setText(R.string.server_info_available);
 			} else {
 				this.mServerInfoCarbons
-						.setText(R.string.server_info_unavailable);
+					.setText(R.string.server_info_unavailable);
 			}
 			if (features.sm()) {
 				this.mServerInfoSm.setText(R.string.server_info_available);
@@ -409,21 +431,21 @@ public class EditAccountActivity extends XmppActivity implements OnAccountUpdate
 				this.mOtrFingerprintBox.setVisibility(View.VISIBLE);
 				this.mOtrFingerprint.setText(CryptoHelper.prettifyFingerprint(fingerprint));
 				this.mOtrFingerprintToClipboardButton
-						.setVisibility(View.VISIBLE);
+					.setVisibility(View.VISIBLE);
 				this.mOtrFingerprintToClipboardButton
-						.setOnClickListener(new View.OnClickListener() {
+					.setOnClickListener(new View.OnClickListener() {
 
-							@Override
-							public void onClick(View v) {
+						@Override
+						public void onClick(View v) {
 
-								if (copyTextToClipboard(fingerprint, R.string.otr_fingerprint)) {
-									Toast.makeText(
-											EditAccountActivity.this,
-											R.string.toast_message_otr_fingerprint,
-											Toast.LENGTH_SHORT).show();
-								}
+							if (copyTextToClipboard(fingerprint, R.string.otr_fingerprint)) {
+								Toast.makeText(
+										EditAccountActivity.this,
+										R.string.toast_message_otr_fingerprint,
+										Toast.LENGTH_SHORT).show();
 							}
-						});
+						}
+					});
 			} else {
 				this.mOtrFingerprintBox.setVisibility(View.GONE);
 			}
diff --git a/src/main/java/eu/siacs/conversations/ui/ShareWithActivity.java b/src/main/java/eu/siacs/conversations/ui/ShareWithActivity.java
index be5eee99..c8075514 100644
--- a/src/main/java/eu/siacs/conversations/ui/ShareWithActivity.java
+++ b/src/main/java/eu/siacs/conversations/ui/ShareWithActivity.java
@@ -117,10 +117,10 @@ public class ShareWithActivity extends XmppActivity {
 	}
 
 	@Override
-	public boolean onOptionsItemSelected(MenuItem item) {
+	public boolean onOptionsItemSelected(final MenuItem item) {
 		switch (item.getItemId()) {
 		case R.id.action_add:
-			Intent intent = new Intent(getApplicationContext(),
+			final Intent intent = new Intent(getApplicationContext(),
 					ChooseContactActivity.class);
 			startActivityForResult(intent, REQUEST_START_NEW_CONVERSATION);
 			return true;
diff --git a/src/main/java/eu/siacs/conversations/ui/StartConversationActivity.java b/src/main/java/eu/siacs/conversations/ui/StartConversationActivity.java
index 4fdcf79e..630dc6ef 100644
--- a/src/main/java/eu/siacs/conversations/ui/StartConversationActivity.java
+++ b/src/main/java/eu/siacs/conversations/ui/StartConversationActivity.java
@@ -53,19 +53,21 @@ import java.util.List;
 import eu.siacs.conversations.Config;
 import eu.siacs.conversations.R;
 import eu.siacs.conversations.entities.Account;
+import eu.siacs.conversations.entities.Blockable;
 import eu.siacs.conversations.entities.Bookmark;
 import eu.siacs.conversations.entities.Contact;
 import eu.siacs.conversations.entities.Conversation;
 import eu.siacs.conversations.entities.ListItem;
-import eu.siacs.conversations.utils.XmppUri;
 import eu.siacs.conversations.services.XmppConnectionService.OnRosterUpdate;
 import eu.siacs.conversations.ui.adapter.KnownHostsAdapter;
 import eu.siacs.conversations.ui.adapter.ListItemAdapter;
 import eu.siacs.conversations.utils.Validator;
+import eu.siacs.conversations.utils.XmppUri;
+import eu.siacs.conversations.xmpp.OnUpdateBlocklist;
 import eu.siacs.conversations.xmpp.jid.InvalidJidException;
 import eu.siacs.conversations.xmpp.jid.Jid;
 
-public class StartConversationActivity extends XmppActivity implements OnRosterUpdate {
+public class StartConversationActivity extends XmppActivity implements OnRosterUpdate, OnUpdateBlocklist {
 
 	public int conference_context_id;
 	public int contact_context_id;
@@ -133,7 +135,9 @@ public class StartConversationActivity extends XmppActivity implements OnRosterU
 	private ViewPager.SimpleOnPageChangeListener mOnPageChangeListener = new ViewPager.SimpleOnPageChangeListener() {
 		@Override
 		public void onPageSelected(int position) {
-			getActionBar().setSelectedNavigationItem(position);
+			if (getActionBar() != null) {
+				getActionBar().setSelectedNavigationItem(position);
+			}
 			onTabChanged();
 		}
 	};
@@ -146,12 +150,12 @@ public class StartConversationActivity extends XmppActivity implements OnRosterU
 
 		@Override
 		public void beforeTextChanged(CharSequence s, int start, int count,
-									  int after) {
+				int after) {
 		}
 
 		@Override
 		public void onTextChanged(CharSequence s, int start, int before,
-								  int count) {
+				int count) {
 		}
 	};
 	private MenuItem mMenuSearchView;
@@ -179,9 +183,9 @@ public class StartConversationActivity extends XmppActivity implements OnRosterU
 		actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
 
 		mContactsTab = actionBar.newTab().setText(R.string.contacts)
-				.setTabListener(mTabListener);
+			.setTabListener(mTabListener);
 		mConferencesTab = actionBar.newTab().setText(R.string.conferences)
-				.setTabListener(mTabListener);
+			.setTabListener(mTabListener);
 		actionBar.addTab(mContactsTab);
 		actionBar.addTab(mConferencesTab);
 
@@ -207,35 +211,35 @@ public class StartConversationActivity extends XmppActivity implements OnRosterU
 		mConferenceListFragment.setListAdapter(mConferenceAdapter);
 		mConferenceListFragment.setContextMenu(R.menu.conference_context);
 		mConferenceListFragment
-				.setOnListItemClickListener(new OnItemClickListener() {
+			.setOnListItemClickListener(new OnItemClickListener() {
 
-					@Override
-					public void onItemClick(AdapterView<?> arg0, View arg1,
-											int position, long arg3) {
-						openConversationForBookmark(position);
-					}
-				});
+				@Override
+				public void onItemClick(AdapterView<?> arg0, View arg1,
+						int position, long arg3) {
+					openConversationForBookmark(position);
+				}
+			});
 
 		mContactsAdapter = new ListItemAdapter(this, contacts);
 		mContactsListFragment.setListAdapter(mContactsAdapter);
 		mContactsListFragment.setContextMenu(R.menu.contact_context);
 		mContactsListFragment
-				.setOnListItemClickListener(new OnItemClickListener() {
+			.setOnListItemClickListener(new OnItemClickListener() {
 
-					@Override
-					public void onItemClick(AdapterView<?> arg0, View arg1,
-											int position, long arg3) {
-						openConversationForContact(position);
-					}
-				});
+				@Override
+				public void onItemClick(AdapterView<?> arg0, View arg1,
+						int position, long arg3) {
+					openConversationForContact(position);
+				}
+			});
 
 	}
 
 	protected void openConversationForContact(int position) {
 		Contact contact = (Contact) contacts.get(position);
 		Conversation conversation = xmppConnectionService
-				.findOrCreateConversation(contact.getAccount(),
-						contact.getJid(), false);
+			.findOrCreateConversation(contact.getAccount(),
+					contact.getJid(), false);
 		switchToConversation(conversation);
 	}
 
@@ -251,8 +255,8 @@ public class StartConversationActivity extends XmppActivity implements OnRosterU
 	protected void openConversationForBookmark(int position) {
 		Bookmark bookmark = (Bookmark) conferences.get(position);
 		Conversation conversation = xmppConnectionService
-				.findOrCreateConversation(bookmark.getAccount(),
-						bookmark.getJid(), true);
+			.findOrCreateConversation(bookmark.getAccount(),
+					bookmark.getJid(), true);
 		conversation.setBookmark(bookmark);
 		if (!conversation.getMucOptions().online()) {
 			xmppConnectionService.joinMuc(conversation);
@@ -270,14 +274,19 @@ public class StartConversationActivity extends XmppActivity implements OnRosterU
 		switchToContactDetails(contact);
 	}
 
+	protected void toggleContactBlock() {
+		final int position = contact_context_id;
+		BlockContactDialog.show(this, xmppConnectionService, (Contact)contacts.get(position));
+	}
+
 	protected void deleteContact() {
-		int position = contact_context_id;
+		final int position = contact_context_id;
 		final Contact contact = (Contact) contacts.get(position);
-		AlertDialog.Builder builder = new AlertDialog.Builder(this);
+		final AlertDialog.Builder builder = new AlertDialog.Builder(this);
 		builder.setNegativeButton(R.string.cancel, null);
 		builder.setTitle(R.string.action_delete_contact);
 		builder.setMessage(getString(R.string.remove_contact_text,
-				contact.getJid()));
+					contact.getJid()));
 		builder.setPositiveButton(R.string.delete, new OnClickListener() {
 
 			@Override
@@ -287,7 +296,6 @@ public class StartConversationActivity extends XmppActivity implements OnRosterU
 			}
 		});
 		builder.create().show();
-
 	}
 
 	protected void deleteConference() {
@@ -298,7 +306,7 @@ public class StartConversationActivity extends XmppActivity implements OnRosterU
 		builder.setNegativeButton(R.string.cancel, null);
 		builder.setTitle(R.string.delete_bookmark);
 		builder.setMessage(getString(R.string.remove_bookmark_text,
-				bookmark.getJid()));
+					bookmark.getJid()));
 		builder.setPositiveButton(R.string.delete, new OnClickListener() {
 
 			@Override
@@ -360,7 +368,7 @@ public class StartConversationActivity extends XmppActivity implements OnRosterU
 								return;
 							}
 							Account account = xmppConnectionService
-									.findAccountByJid(accountJid);
+								.findAccountByJid(accountJid);
 							if (account == null) {
 								dialog.dismiss();
 								return;
@@ -395,7 +403,7 @@ public class StartConversationActivity extends XmppActivity implements OnRosterU
 		}
 		populateAccountSpinner(spinner);
 		final CheckBox bookmarkCheckBox = (CheckBox) dialogView
-				.findViewById(R.id.bookmark);
+			.findViewById(R.id.bookmark);
 		builder.setView(dialogView);
 		builder.setNegativeButton(R.string.cancel, null);
 		builder.setPositiveButton(R.string.join, null);
@@ -424,7 +432,7 @@ public class StartConversationActivity extends XmppActivity implements OnRosterU
 								return;
 							}
 							Account account = xmppConnectionService
-									.findAccountByJid(accountJid);
+								.findAccountByJid(accountJid);
 							if (account == null) {
 								dialog.dismiss();
 								return;
@@ -438,22 +446,22 @@ public class StartConversationActivity extends XmppActivity implements OnRosterU
 									bookmark.setAutojoin(true);
 									account.getBookmarks().add(bookmark);
 									xmppConnectionService
-											.pushBookmarks(account);
+										.pushBookmarks(account);
 									Conversation conversation = xmppConnectionService
-											.findOrCreateConversation(account,
-													conferenceJid, true);
+										.findOrCreateConversation(account,
+												conferenceJid, true);
 									conversation.setBookmark(bookmark);
 									if (!conversation.getMucOptions().online()) {
 										xmppConnectionService
-												.joinMuc(conversation);
+											.joinMuc(conversation);
 									}
 									dialog.dismiss();
 									switchToConversation(conversation);
 								}
 							} else {
 								Conversation conversation = xmppConnectionService
-										.findOrCreateConversation(account,
-												conferenceJid, true);
+									.findOrCreateConversation(account,
+											conferenceJid, true);
 								if (!conversation.getMucOptions().online()) {
 									xmppConnectionService.joinMuc(conversation);
 								}
@@ -469,8 +477,8 @@ public class StartConversationActivity extends XmppActivity implements OnRosterU
 
 	protected void switchToConversation(Contact contact) {
 		Conversation conversation = xmppConnectionService
-				.findOrCreateConversation(contact.getAccount(),
-						contact.getJid(), false);
+			.findOrCreateConversation(contact.getAccount(),
+					contact.getJid(), false);
 		switchToConversation(conversation);
 	}
 
@@ -486,14 +494,14 @@ public class StartConversationActivity extends XmppActivity implements OnRosterU
 		this.mOptionsMenu = menu;
 		getMenuInflater().inflate(R.menu.start_conversation, menu);
 		MenuItem menuCreateContact = menu
-				.findItem(R.id.action_create_contact);
+			.findItem(R.id.action_create_contact);
 		MenuItem menuCreateConference = menu
-				.findItem(R.id.action_join_conference);
+			.findItem(R.id.action_join_conference);
 		mMenuSearchView = menu.findItem(R.id.action_search);
 		mMenuSearchView.setOnActionExpandListener(mOnActionExpandListener);
 		View mSearchView = mMenuSearchView.getActionView();
 		mSearchEditText = (EditText) mSearchView
-				.findViewById(R.id.search_field);
+			.findViewById(R.id.search_field);
 		mSearchEditText.addTextChangedListener(mSearchTextWatcher);
 		if (getActionBar().getSelectedNavigationIndex() == 0) {
 			menuCreateConference.setVisible(false);
@@ -562,7 +570,7 @@ public class StartConversationActivity extends XmppActivity implements OnRosterU
 		}
 		this.mKnownHosts = xmppConnectionService.getKnownHosts();
 		this.mKnownConferenceHosts = xmppConnectionService
-				.getKnownConferenceHosts();
+			.getKnownConferenceHosts();
 		if (this.mPendingInvite != null) {
 			mPendingInvite.invite();
 			this.mPendingInvite = null;
@@ -604,7 +612,7 @@ public class StartConversationActivity extends XmppActivity implements OnRosterU
 											byte[] payload = record.getPayload();
 											if (payload[0] == 0) {
 												return new Invite(Uri.parse(new String(Arrays.copyOfRange(
-														payload, 1, payload.length)))).invite();
+																	payload, 1, payload.length)))).invite();
 											}
 										}
 									}
@@ -685,16 +693,29 @@ public class StartConversationActivity extends XmppActivity implements OnRosterU
 		invalidateOptionsMenu();
 	}
 
+	@Override
+	public void OnUpdateBlocklist(final Status status) {
+		runOnUiThread(new Runnable() {
+
+			@Override
+			public void run() {
+				if (mSearchEditText != null) {
+					filter(mSearchEditText.getText().toString());
+				}
+			}
+		});
+	}
+
 	public static class MyListFragment extends ListFragment {
 		private AdapterView.OnItemClickListener mOnItemClickListener;
 		private int mResContextMenu;
 
-		public void setContextMenu(int res) {
+		public void setContextMenu(final int res) {
 			this.mResContextMenu = res;
 		}
 
 		@Override
-		public void onListItemClick(ListView l, View v, int position, long id) {
+		public void onListItemClick(final ListView l, final View v, final int position, final long id) {
 			if (mOnItemClickListener != null) {
 				mOnItemClickListener.onItemClick(l, v, position, id);
 			}
@@ -705,28 +726,38 @@ public class StartConversationActivity extends XmppActivity implements OnRosterU
 		}
 
 		@Override
-		public void onViewCreated(View view, Bundle savedInstanceState) {
+		public void onViewCreated(final View view, final Bundle savedInstanceState) {
 			super.onViewCreated(view, savedInstanceState);
 			registerForContextMenu(getListView());
 			getListView().setFastScrollEnabled(true);
 		}
 
 		@Override
-		public void onCreateContextMenu(ContextMenu menu, View v,
-										ContextMenuInfo menuInfo) {
+		public void onCreateContextMenu(final ContextMenu menu, final View v,
+				final ContextMenuInfo menuInfo) {
 			super.onCreateContextMenu(menu, v, menuInfo);
-			StartConversationActivity activity = (StartConversationActivity) getActivity();
+			final StartConversationActivity activity = (StartConversationActivity) getActivity();
 			activity.getMenuInflater().inflate(mResContextMenu, menu);
-			AdapterView.AdapterContextMenuInfo acmi = (AdapterContextMenuInfo) menuInfo;
+			final AdapterView.AdapterContextMenuInfo acmi = (AdapterContextMenuInfo) menuInfo;
 			if (mResContextMenu == R.menu.conference_context) {
 				activity.conference_context_id = acmi.position;
 			} else {
 				activity.contact_context_id = acmi.position;
+				final Blockable contact = (Contact) activity.contacts.get(acmi.position);
+
+				final MenuItem blockUnblockItem = menu.findItem(R.id.context_contact_block_unblock);
+				if (blockUnblockItem != null) {
+					if (contact.isBlocked()) {
+						blockUnblockItem.setTitle(R.string.unblock_contact);
+					} else {
+						blockUnblockItem.setTitle(R.string.block_contact);
+					}
+				}
 			}
 		}
 
 		@Override
-		public boolean onContextItemSelected(MenuItem item) {
+		public boolean onContextItemSelected(final MenuItem item) {
 			StartConversationActivity activity = (StartConversationActivity) getActivity();
 			switch (item.getItemId()) {
 				case R.id.context_start_conversation:
@@ -735,6 +766,9 @@ public class StartConversationActivity extends XmppActivity implements OnRosterU
 				case R.id.context_contact_details:
 					activity.openDetailsForContact();
 					break;
+				case R.id.context_contact_block_unblock:
+					activity.toggleContactBlock();
+					break;
 				case R.id.context_delete_contact:
 					activity.deleteContact();
 					break;
@@ -750,11 +784,11 @@ public class StartConversationActivity extends XmppActivity implements OnRosterU
 
 	private class Invite extends XmppUri {
 
-		public Invite(Uri uri) {
+		public Invite(final Uri uri) {
 			super(uri);
 		}
 
-		public Invite(String uri) {
+		public Invite(final String uri) {
 			super(uri);
 		}
 
diff --git a/src/main/java/eu/siacs/conversations/ui/XmppActivity.java b/src/main/java/eu/siacs/conversations/ui/XmppActivity.java
index e6ae2a1c..69dd47e7 100644
--- a/src/main/java/eu/siacs/conversations/ui/XmppActivity.java
+++ b/src/main/java/eu/siacs/conversations/ui/XmppActivity.java
@@ -71,6 +71,7 @@ import eu.siacs.conversations.services.AvatarService;
 import eu.siacs.conversations.services.XmppConnectionService;
 import eu.siacs.conversations.services.XmppConnectionService.XmppConnectionBinder;
 import eu.siacs.conversations.utils.ExceptionHelper;
+import eu.siacs.conversations.xmpp.OnUpdateBlocklist;
 import eu.siacs.conversations.xmpp.jid.InvalidJidException;
 import eu.siacs.conversations.xmpp.jid.Jid;
 
@@ -199,7 +200,7 @@ public abstract class XmppActivity extends Activity {
 							xmppConnectionServiceBound = false;
 						}
 						stopService(new Intent(XmppActivity.this,
-								XmppConnectionService.class));
+									XmppConnectionService.class));
 						finish();
 					}
 				});
@@ -209,13 +210,13 @@ public abstract class XmppActivity extends Activity {
 					@Override
 					public void onClick(DialogInterface dialog, int which) {
 						Uri uri = Uri
-								.parse("market://details?id=org.sufficientlysecure.keychain");
+							.parse("market://details?id=org.sufficientlysecure.keychain");
 						Intent marketIntent = new Intent(Intent.ACTION_VIEW,
 								uri);
 						PackageManager manager = getApplicationContext()
-								.getPackageManager();
+							.getPackageManager();
 						List<ResolveInfo> infos = manager
-								.queryIntentActivities(marketIntent, 0);
+							.queryIntentActivities(marketIntent, 0);
 						if (infos.size() > 0) {
 							startActivity(marketIntent);
 						} else {
@@ -245,6 +246,9 @@ public abstract class XmppActivity extends Activity {
 		if (this instanceof XmppConnectionService.OnMucRosterUpdate) {
 			this.xmppConnectionService.setOnMucRosterUpdateListener((XmppConnectionService.OnMucRosterUpdate) this);
 		}
+		if (this instanceof OnUpdateBlocklist) {
+			this.xmppConnectionService.setOnUpdateBlocklistListener((OnUpdateBlocklist) this);
+		}
 	}
 
 	protected void unregisterListeners() {
@@ -260,9 +264,13 @@ public abstract class XmppActivity extends Activity {
 		if (this instanceof XmppConnectionService.OnMucRosterUpdate) {
 			this.xmppConnectionService.removeOnMucRosterUpdateListener();
 		}
+		if (this instanceof OnUpdateBlocklist) {
+			this.xmppConnectionService.removeOnUpdateBlocklistListener();
+		}
 	}
 
-	public boolean onOptionsItemSelected(MenuItem item) {
+	@Override
+	public boolean onOptionsItemSelected(final MenuItem item) {
 		switch (item.getItemId()) {
 			case R.id.action_settings:
 				startActivity(new Intent(this, SettingsActivity.class));
@@ -300,7 +308,7 @@ public abstract class XmppActivity extends Activity {
 
 	protected SharedPreferences getPreferences() {
 		return PreferenceManager
-				.getDefaultSharedPreferences(getApplicationContext());
+			.getDefaultSharedPreferences(getApplicationContext());
 	}
 
 	public boolean useSubjectToIdentifyConference() {
@@ -312,7 +320,7 @@ public abstract class XmppActivity extends Activity {
 	}
 
 	public void switchToConversation(Conversation conversation, String text,
-									 boolean newTask) {
+			boolean newTask) {
 		switchToConversation(conversation,text,null,newTask);
 	}
 
@@ -372,7 +380,7 @@ public abstract class XmppActivity extends Activity {
 
 					@Override
 					public void userInputRequried(PendingIntent pi,
-												  Account account) {
+							Account account) {
 						try {
 							startIntentSenderForResult(pi.getIntentSender(),
 									REQUEST_ANNOUNCE_PGP, null, 0, 0, 0);
@@ -383,15 +391,15 @@ public abstract class XmppActivity extends Activity {
 					@Override
 					public void success(Account account) {
 						xmppConnectionService.databaseBackend
-								.updateAccount(account);
+							.updateAccount(account);
 						xmppConnectionService.sendPresencePacket(account,
 								xmppConnectionService.getPresenceGenerator()
-										.sendPresence(account));
+								.sendPresence(account));
 						if (conversation != null) {
 							conversation
-									.setNextEncryption(Message.ENCRYPTION_PGP);
+								.setNextEncryption(Message.ENCRYPTION_PGP);
 							xmppConnectionService.databaseBackend
-									.updateConversation(conversation);
+								.updateConversation(conversation);
 						}
 					}
 
@@ -420,7 +428,7 @@ public abstract class XmppActivity extends Activity {
 	}
 
 	protected void showAddToRosterDialog(final Conversation conversation) {
-		final Jid jid = conversation.getContactJid();
+		final Jid jid = conversation.getJid();
 		AlertDialog.Builder builder = new AlertDialog.Builder(this);
 		builder.setTitle(jid.toString());
 		builder.setMessage(getString(R.string.not_in_roster));
@@ -430,7 +438,7 @@ public abstract class XmppActivity extends Activity {
 
 					@Override
 					public void onClick(DialogInterface dialog, int which) {
-						final Jid jid = conversation.getContactJid();
+						final Jid jid = conversation.getJid();
 						Account account = conversation.getAccount();
 						Contact contact = account.getRoster().getContact(jid);
 						xmppConnectionService.createContact(contact);
@@ -462,7 +470,7 @@ public abstract class XmppActivity extends Activity {
 	}
 
 	private void warnMutalPresenceSubscription(final Conversation conversation,
-											   final OnPresenceSelected listener) {
+			final OnPresenceSelected listener) {
 		AlertDialog.Builder builder = new AlertDialog.Builder(this);
 		builder.setTitle(conversation.getContact().getJid().toString());
 		builder.setMessage(R.string.without_mutual_presence_updates);
@@ -485,13 +493,13 @@ public abstract class XmppActivity extends Activity {
 	}
 
 	protected void quickPasswordEdit(String previousValue,
-									 OnValueEdited callback) {
+			OnValueEdited callback) {
 		quickEdit(previousValue, callback, true);
 	}
 
 	@SuppressLint("InflateParams")
 	private void quickEdit(final String previousValue,
-						   final OnValueEdited callback, boolean password) {
+			final OnValueEdited callback, boolean password) {
 		AlertDialog.Builder builder = new AlertDialog.Builder(this);
 		View view = getLayoutInflater().inflate(R.layout.quickedit, null);
 		final EditText editor = (EditText) view.findViewById(R.id.editor);
@@ -521,7 +529,7 @@ public abstract class XmppActivity extends Activity {
 	}
 
 	public void selectPresence(final Conversation conversation,
-							   final OnPresenceSelected listener) {
+			final OnPresenceSelected listener) {
 		final Contact contact = conversation.getContact();
 		if (conversation.hasValidOtrSession()) {
 			SessionID id = conversation.getOtrSession().getSessionID();
@@ -576,7 +584,7 @@ public abstract class XmppActivity extends Activity {
 
 							@Override
 							public void onClick(DialogInterface dialog,
-												int which) {
+									int which) {
 								presence.delete(0, presence.length());
 								presence.append(presencesArray[which]);
 							}
@@ -600,7 +608,7 @@ public abstract class XmppActivity extends Activity {
 	}
 
 	protected void onActivityResult(int requestCode, int resultCode,
-									final Intent data) {
+			final Intent data) {
 		super.onActivityResult(requestCode, resultCode, data);
 		if (requestCode == REQUEST_INVITE_TO_CONVERSATION
 				&& resultCode == RESULT_OK) {
@@ -608,19 +616,19 @@ public abstract class XmppActivity extends Activity {
 				Jid jid = Jid.fromString(data.getStringExtra("contact"));
 				String conversationUuid = data.getStringExtra("conversation");
 				Conversation conversation = xmppConnectionService
-						.findConversationByUuid(conversationUuid);
+					.findConversationByUuid(conversationUuid);
 				if (conversation.getMode() == Conversation.MODE_MULTI) {
 					xmppConnectionService.invite(conversation, jid);
 				} else {
 					List<Jid> jids = new ArrayList<Jid>();
-					jids.add(conversation.getContactJid().toBareJid());
+					jids.add(conversation.getJid().toBareJid());
 					jids.add(jid);
 					xmppConnectionService.createAdhocConference(conversation.getAccount(), jids, adhocCallback);
 				}
 			} catch (final InvalidJidException ignored) {
 
 			}
-		}
+				}
 	}
 
 	private UiCallback<Conversation> adhocCallback = new UiCallback<Conversation>() {
@@ -688,18 +696,18 @@ public abstract class XmppActivity extends Activity {
 	}
 
 	protected void registerNdefPushMessageCallback() {
-			NfcAdapter nfcAdapter = NfcAdapter.getDefaultAdapter(this);
-			if (nfcAdapter != null && nfcAdapter.isEnabled()) {
-				nfcAdapter.setNdefPushMessageCallback(new NfcAdapter.CreateNdefMessageCallback() {
-					@Override
-					public NdefMessage createNdefMessage(NfcEvent nfcEvent) {
-                        return new NdefMessage(new NdefRecord[]{
-                                NdefRecord.createUri(getShareableUri()),
-                                NdefRecord.createApplicationRecord("eu.siacs.conversations")
-                        });
-					}
-				}, this);
-			}
+		NfcAdapter nfcAdapter = NfcAdapter.getDefaultAdapter(this);
+		if (nfcAdapter != null && nfcAdapter.isEnabled()) {
+			nfcAdapter.setNdefPushMessageCallback(new NfcAdapter.CreateNdefMessageCallback() {
+				@Override
+				public NdefMessage createNdefMessage(NfcEvent nfcEvent) {
+					return new NdefMessage(new NdefRecord[]{
+						NdefRecord.createUri(getShareableUri()),
+							NdefRecord.createApplicationRecord("eu.siacs.conversations")
+					});
+				}
+			}, this);
+		}
 	}
 
 	protected void unregisterNdefPushMessageCallback() {
@@ -831,13 +839,13 @@ public abstract class XmppActivity extends Activity {
 				try {
 					task.execute(message);
 				} catch (final RejectedExecutionException ignored) {
-                }
+				}
 			}
 		}
 	}
 
 	public static boolean cancelPotentialWork(Message message,
-											  ImageView imageView) {
+			ImageView imageView) {
 		final BitmapWorkerTask bitmapWorkerTask = getBitmapWorkerTask(imageView);
 
 		if (bitmapWorkerTask != null) {
@@ -866,7 +874,7 @@ public abstract class XmppActivity extends Activity {
 		private final WeakReference<BitmapWorkerTask> bitmapWorkerTaskReference;
 
 		public AsyncDrawable(Resources res, Bitmap bitmap,
-							 BitmapWorkerTask bitmapWorkerTask) {
+				BitmapWorkerTask bitmapWorkerTask) {
 			super(res, bitmap);
 			bitmapWorkerTaskReference = new WeakReference<>(
 					bitmapWorkerTask);
diff --git a/src/main/java/eu/siacs/conversations/ui/adapter/ConversationAdapter.java b/src/main/java/eu/siacs/conversations/ui/adapter/ConversationAdapter.java
index f728e800..2465380f 100644
--- a/src/main/java/eu/siacs/conversations/ui/adapter/ConversationAdapter.java
+++ b/src/main/java/eu/siacs/conversations/ui/adapter/ConversationAdapter.java
@@ -34,7 +34,7 @@ public class ConversationAdapter extends ArrayAdapter<Conversation> {
 	public View getView(int position, View view, ViewGroup parent) {
 		if (view == null) {
 			LayoutInflater inflater = (LayoutInflater) activity
-					.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
+				.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
 			view = inflater.inflate(R.layout.conversation_list_row,
 					parent, false);
 		}
@@ -53,19 +53,19 @@ public class ConversationAdapter extends ArrayAdapter<Conversation> {
 			}
 		}
 		TextView convName = (TextView) view
-				.findViewById(R.id.conversation_name);
+			.findViewById(R.id.conversation_name);
 		if (conversation.getMode() == Conversation.MODE_SINGLE
 				|| activity.useSubjectToIdentifyConference()) {
 			convName.setText(conversation.getName());
 		} else {
-			convName.setText(conversation.getContactJid().toBareJid().toString());
+			convName.setText(conversation.getJid().toBareJid().toString());
 		}
 		TextView mLastMessage = (TextView) view
-				.findViewById(R.id.conversation_lastmsg);
+			.findViewById(R.id.conversation_lastmsg);
 		TextView mTimestamp = (TextView) view
-				.findViewById(R.id.conversation_lastupdate);
+			.findViewById(R.id.conversation_lastupdate);
 		ImageView imagePreview = (ImageView) view
-				.findViewById(R.id.conversation_lastimage);
+			.findViewById(R.id.conversation_lastimage);
 
 		Message message = conversation.getLatestMessage();
 
@@ -151,12 +151,12 @@ public class ConversationAdapter extends ArrayAdapter<Conversation> {
 			imagePreview.setVisibility(View.GONE);
 		}
 		mTimestamp.setText(UIHelper.readableTimeDifference(getContext(),
-				conversation.getLatestMessage().getTimeSent()));
+					conversation.getLatestMessage().getTimeSent()));
 
 		ImageView profilePicture = (ImageView) view
-				.findViewById(R.id.conversation_image);
+			.findViewById(R.id.conversation_image);
 		profilePicture.setImageBitmap(activity.avatarService().get(
-				conversation, activity.getPixel(56)));
+					conversation, activity.getPixel(56)));
 
 		return view;
 	}
diff --git a/src/main/java/eu/siacs/conversations/utils/Xmlns.java b/src/main/java/eu/siacs/conversations/utils/Xmlns.java
new file mode 100644
index 00000000..932e48ae
--- /dev/null
+++ b/src/main/java/eu/siacs/conversations/utils/Xmlns.java
@@ -0,0 +1,5 @@
+package eu.siacs.conversations.utils;
+
+public final class Xmlns {
+	public static final String BLOCKING = "urn:xmpp:blocking";
+}
diff --git a/src/main/java/eu/siacs/conversations/utils/XmppUri.java b/src/main/java/eu/siacs/conversations/utils/XmppUri.java
index a9b8d1c0..d7c3bce5 100644
--- a/src/main/java/eu/siacs/conversations/utils/XmppUri.java
+++ b/src/main/java/eu/siacs/conversations/utils/XmppUri.java
@@ -5,7 +5,6 @@ import android.net.Uri;
 import java.io.UnsupportedEncodingException;
 import java.net.URLDecoder;
 
-import eu.siacs.conversations.utils.CryptoHelper;
 import eu.siacs.conversations.xmpp.jid.InvalidJidException;
 import eu.siacs.conversations.xmpp.jid.Jid;
 
diff --git a/src/main/java/eu/siacs/conversations/xml/Element.java b/src/main/java/eu/siacs/conversations/xml/Element.java
index 9455d9e8..51708759 100644
--- a/src/main/java/eu/siacs/conversations/xml/Element.java
+++ b/src/main/java/eu/siacs/conversations/xml/Element.java
@@ -62,16 +62,16 @@ public class Element {
 			if (child.getName().equals(name)
 					&& (child.getAttribute("xmlns").equals(xmlns))) {
 				return child;
-			}
+					}
 		}
 		return null;
 	}
 
-	public boolean hasChild(String name) {
+	public boolean hasChild(final String name) {
 		return findChild(name) != null;
 	}
 
-	public boolean hasChild(String name, String xmlns) {
+	public boolean hasChild(final String name, final String xmlns) {
 		return findChild(name, xmlns) != null;
 	}
 
@@ -110,15 +110,15 @@ public class Element {
 
 	public Jid getAttributeAsJid(String name) {
 		final String jid = this.getAttribute(name);
-        if (jid != null && !jid.isEmpty()) {
-            try {
-                return Jid.fromString(jid);
-            } catch (final InvalidJidException e) {
+		if (jid != null && !jid.isEmpty()) {
+			try {
+				return Jid.fromString(jid);
+			} catch (final InvalidJidException e) {
 				Log.e(Config.LOGTAG, "could not parse jid " + jid);
-                return null;
-            }
-        }
-        return null;
+				return null;
+			}
+		}
+		return null;
 	}
 
 	public Hashtable<String, String> getAttributes() {
diff --git a/src/main/java/eu/siacs/conversations/xmpp/OnContactStatusChanged.java b/src/main/java/eu/siacs/conversations/xmpp/OnContactStatusChanged.java
index 849e8e76..20b17f02 100644
--- a/src/main/java/eu/siacs/conversations/xmpp/OnContactStatusChanged.java
+++ b/src/main/java/eu/siacs/conversations/xmpp/OnContactStatusChanged.java
@@ -3,5 +3,5 @@ package eu.siacs.conversations.xmpp;
 import eu.siacs.conversations.entities.Contact;
 
 public interface OnContactStatusChanged {
-	public void onContactStatusChanged(Contact contact, boolean online);
+	public void onContactStatusChanged(final Contact contact, final boolean online);
 }
diff --git a/src/main/java/eu/siacs/conversations/xmpp/OnUpdateBlocklist.java b/src/main/java/eu/siacs/conversations/xmpp/OnUpdateBlocklist.java
new file mode 100644
index 00000000..92e72cfa
--- /dev/null
+++ b/src/main/java/eu/siacs/conversations/xmpp/OnUpdateBlocklist.java
@@ -0,0 +1,13 @@
+package eu.siacs.conversations.xmpp;
+
+public interface OnUpdateBlocklist {
+	// Use an enum instead of a boolean to make sure we don't run into the boolean trap
+	// (`onUpdateBlocklist(true)' doesn't read well, and could be confusing).
+	public static enum Status {
+		BLOCKED,
+		UNBLOCKED
+	}
+
+	@SuppressWarnings("MethodNameSameAsClassName")
+	public void OnUpdateBlocklist(final Status status);
+}
diff --git a/src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java b/src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java
index b090d651..7fd0a4b6 100644
--- a/src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java
+++ b/src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java
@@ -30,10 +30,12 @@ import java.security.KeyManagementException;
 import java.security.NoSuchAlgorithmException;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.HashMap;
 import java.util.Hashtable;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Map;
 import java.util.Map.Entry;
 
 import javax.net.ssl.HostnameVerifier;
@@ -48,8 +50,10 @@ import eu.siacs.conversations.crypto.sasl.Plain;
 import eu.siacs.conversations.crypto.sasl.SaslMechanism;
 import eu.siacs.conversations.crypto.sasl.ScramSha1;
 import eu.siacs.conversations.entities.Account;
+import eu.siacs.conversations.generator.IqGenerator;
 import eu.siacs.conversations.services.XmppConnectionService;
 import eu.siacs.conversations.utils.DNSHelper;
+import eu.siacs.conversations.utils.Xmlns;
 import eu.siacs.conversations.xml.Element;
 import eu.siacs.conversations.xml.Tag;
 import eu.siacs.conversations.xml.TagWriter;
@@ -76,19 +80,19 @@ public class XmppConnection implements Runnable {
 	private static final int PACKET_PRESENCE = 2;
 	private final Context applicationContext;
 	protected Account account;
-	private WakeLock wakeLock;
+	private final WakeLock wakeLock;
 	private Socket socket;
 	private XmlReader tagReader;
 	private TagWriter tagWriter;
-	private Features features = new Features(this);
+	private final Features features = new Features(this);
 	private boolean shouldBind = true;
 	private boolean shouldAuthenticate = true;
 	private Element streamFeatures;
-	private HashMap<String, List<String>> disco = new HashMap<>();
+	private final HashMap<String, List<String>> disco = new HashMap<>();
 
 	private String streamId = null;
 	private int smVersion = 3;
-	private SparseArray<String> messageReceipts = new SparseArray<>();
+	private final SparseArray<String> messageReceipts = new SparseArray<>();
 
 	private boolean enabledEncryption = false;
 	private boolean enabledCarbons = false;
@@ -100,20 +104,20 @@ public class XmppConnection implements Runnable {
 	private long lastConnect = 0;
 	private long lastSessionStarted = 0;
 	private int attempt = 0;
-	private Hashtable<String, PacketReceived> packetCallbacks = new Hashtable<>();
+	private final Map<String, PacketReceived> packetCallbacks = new Hashtable<>();
 	private OnPresencePacketReceived presenceListener = null;
 	private OnJinglePacketReceived jingleListener = null;
 	private OnIqPacketReceived unregisteredIqListener = null;
 	private OnMessagePacketReceived messageListener = null;
 	private OnStatusChanged statusListener = null;
 	private OnBindListener bindListener = null;
-	private ArrayList<OnAdvancedStreamFeaturesLoaded> advancedStreamFeaturesLoadedListeners = new ArrayList<>();
+	private final ArrayList<OnAdvancedStreamFeaturesLoaded> advancedStreamFeaturesLoadedListeners = new ArrayList<>();
 	private OnMessageAcknowledged acknowledgedListener = null;
 	private XmppConnectionService mXmppConnectionService = null;
 
 	private SaslMechanism saslMechanism;
 
-	public XmppConnection(Account account, XmppConnectionService service) {
+	public XmppConnection(final Account account, final XmppConnectionService service) {
 		this.account = account;
 		this.wakeLock = service.getPowerManager().newWakeLock(
 				PowerManager.PARTIAL_WAKE_LOCK, account.getJid().toBareJid().toString());
@@ -129,7 +133,7 @@ public class XmppConnection implements Runnable {
 					&& (account.getStatus() != Account.State.ONLINE)
 					&& (account.getStatus() != Account.State.DISABLED)) {
 				return;
-			}
+					}
 			if (nextStatus == Account.State.ONLINE) {
 				this.attempt = 0;
 			}
@@ -153,15 +157,15 @@ public class XmppConnection implements Runnable {
 			tagWriter = new TagWriter();
 			packetCallbacks.clear();
 			this.changeStatus(Account.State.CONNECTING);
-			Bundle result = DNSHelper.getSRVRecord(account.getServer());
-			ArrayList<Parcelable> values = result.getParcelableArrayList("values");
+			final Bundle result = DNSHelper.getSRVRecord(account.getServer());
+			final ArrayList<Parcelable> values = result.getParcelableArrayList("values");
 			if ("timeout".equals(result.getString("error"))) {
 				throw new IOException("timeout in dns");
 			} else if (values != null) {
 				int i = 0;
 				boolean socketError = true;
 				while (socketError && values.size() > i) {
-					Bundle namePort = (Bundle) values.get(i);
+					final Bundle namePort = (Bundle) values.get(i);
 					try {
 						String srvRecordServer;
 						try {
@@ -170,9 +174,9 @@ public class XmppConnection implements Runnable {
 							// TODO: Handle me?`
 							srvRecordServer = "";
 						}
-						int srvRecordPort = namePort.getInt("port");
-						String srvIpServer = namePort.getString("ip");
-						InetSocketAddress addr;
+						final int srvRecordPort = namePort.getInt("port");
+						final String srvIpServer = namePort.getString("ip");
+						final InetSocketAddress addr;
 						if (srvIpServer != null) {
 							addr = new InetSocketAddress(srvIpServer, srvRecordPort);
 							Log.d(Config.LOGTAG, account.getJid().toBareJid().toString()
@@ -187,10 +191,10 @@ public class XmppConnection implements Runnable {
 						socket = new Socket();
 						socket.connect(addr, 20000);
 						socketError = false;
-					} catch (UnknownHostException e) {
+					} catch (final UnknownHostException e) {
 						Log.d(Config.LOGTAG, account.getJid().toBareJid().toString() + ": " + e.getMessage());
 						i++;
-					} catch (IOException e) {
+					} catch (final IOException e) {
 						Log.d(Config.LOGTAG, account.getJid().toBareJid().toString() + ": " + e.getMessage());
 						i++;
 					}
@@ -204,9 +208,9 @@ public class XmppConnection implements Runnable {
 			} else {
 				throw new IOException("timeout in dns");
 			}
-			OutputStream out = socket.getOutputStream();
+			final OutputStream out = socket.getOutputStream();
 			tagWriter.setOutputStream(out);
-			InputStream in = socket.getInputStream();
+			final InputStream in = socket.getInputStream();
 			tagReader.setInputStream(in);
 			tagWriter.beginDocument();
 			sendStartStream();
@@ -222,14 +226,9 @@ public class XmppConnection implements Runnable {
 			if (socket.isConnected()) {
 				socket.close();
 			}
-		} catch (UnknownHostException e) {
-			this.changeStatus(Account.State.SERVER_NOT_FOUND);
-		} catch (final ConnectException e) {
+		} catch (final UnknownHostException | ConnectException e) {
 			this.changeStatus(Account.State.SERVER_NOT_FOUND);
-		} catch (final IOException | XmlPullParserException e) {
-			Log.d(Config.LOGTAG, account.getJid().toBareJid().toString() + ": " + e.getMessage());
-			this.changeStatus(Account.State.OFFLINE);
-		} catch (NoSuchAlgorithmException e) {
+		} catch (final IOException | XmlPullParserException | NoSuchAlgorithmException e) {
 			Log.d(Config.LOGTAG, account.getJid().toBareJid().toString() + ": " + e.getMessage());
 			this.changeStatus(Account.State.OFFLINE);
 		} finally {
@@ -268,7 +267,7 @@ public class XmppConnection implements Runnable {
 								}
 								Log.d(Config.LOGTAG, account.getJid().toBareJid().toString() + ": logged in");
 								account.setKey(Account.PINNED_MECHANISM_KEY,
-                                        String.valueOf(saslMechanism.getPriority()));
+										String.valueOf(saslMechanism.getPriority()));
 								tagReader.reset();
 								sendStartStream();
 								processStream(tagReader.readTag());
@@ -289,7 +288,7 @@ public class XmppConnection implements Runnable {
 								}
 								tagWriter.writeElement(response);
 							} else if (nextTag.isStart("enabled")) {
-								Element enabled = tagReader.readElement(nextTag);
+								final Element enabled = tagReader.readElement(nextTag);
 								if ("true".equals(enabled.getAttribute("resume"))) {
 									this.streamId = enabled.getAttribute("id");
 									Log.d(Config.LOGTAG, account.getJid().toBareJid().toString()
@@ -301,14 +300,14 @@ public class XmppConnection implements Runnable {
 								}
 								this.lastSessionStarted = SystemClock.elapsedRealtime();
 								this.stanzasReceived = 0;
-								RequestPacket r = new RequestPacket(smVersion);
+								final RequestPacket r = new RequestPacket(smVersion);
 								tagWriter.writeStanzaAsync(r);
 							} else if (nextTag.isStart("resumed")) {
 								lastPaketReceived = SystemClock.elapsedRealtime();
-								Element resumed = tagReader.readElement(nextTag);
-								String h = resumed.getAttribute("h");
+								final Element resumed = tagReader.readElement(nextTag);
+								final String h = resumed.getAttribute("h");
 								try {
-									int serverCount = Integer.parseInt(h);
+									final int serverCount = Integer.parseInt(h);
 									if (serverCount != stanzasSent) {
 										Log.d(Config.LOGTAG, account.getJid().toBareJid().toString()
 												+ ": session resumed with lost packages");
@@ -327,20 +326,19 @@ public class XmppConnection implements Runnable {
 									}
 									messageReceipts.clear();
 								} catch (final NumberFormatException ignored) {
-
 								}
 								sendServiceDiscoveryInfo(account.getServer());
 								sendServiceDiscoveryItems(account.getServer());
 								sendInitialPing();
 							} else if (nextTag.isStart("r")) {
 								tagReader.readElement(nextTag);
-								AckPacket ack = new AckPacket(this.stanzasReceived, smVersion);
+								final AckPacket ack = new AckPacket(this.stanzasReceived, smVersion);
 								tagWriter.writeStanzaAsync(ack);
 							} else if (nextTag.isStart("a")) {
-								Element ack = tagReader.readElement(nextTag);
+								final Element ack = tagReader.readElement(nextTag);
 								lastPaketReceived = SystemClock.elapsedRealtime();
-								int serverSequence = Integer.parseInt(ack.getAttribute("h"));
-								String msgId = this.messageReceipts.get(serverSequence);
+								final int serverSequence = Integer.parseInt(ack.getAttribute("h"));
+								final String msgId = this.messageReceipts.get(serverSequence);
 								if (msgId != null) {
 									if (this.acknowledgedListener != null) {
 										this.acknowledgedListener.onMessageAcknowledged(
@@ -374,13 +372,12 @@ public class XmppConnection implements Runnable {
 
 	private void sendInitialPing() {
 		Log.d(Config.LOGTAG, account.getJid().toBareJid().toString() + ": sending intial ping");
-		IqPacket iq = new IqPacket(IqPacket.TYPE_GET);
+		final IqPacket iq = new IqPacket(IqPacket.TYPE_GET);
 		iq.setFrom(account.getJid());
 		iq.addChild("ping", "urn:xmpp:ping");
 		this.sendIqPacket(iq, new OnIqPacketReceived() {
-
 			@Override
-			public void onIqPacketReceived(Account account, IqPacket packet) {
+			public void onIqPacketReceived(final Account account, final IqPacket packet) {
 				Log.d(Config.LOGTAG, account.getJid().toBareJid().toString()
 						+ ": online with resource " + account.getResource());
 				changeStatus(Account.State.ONLINE);
@@ -388,7 +385,7 @@ public class XmppConnection implements Runnable {
 		});
 	}
 
-	private Element processPacket(Tag currentTag, int packetType)
+	private Element processPacket(final Tag currentTag, final int packetType)
 		throws XmlPullParserException, IOException {
 		Element element;
 		switch (packetType) {
@@ -411,8 +408,8 @@ public class XmppConnection implements Runnable {
 		}
 		while (!nextTag.isEnd(element.getName())) {
 			if (!nextTag.isNo()) {
-				Element child = tagReader.readElement(nextTag);
-				String type = currentTag.getAttribute("type");
+				final Element child = tagReader.readElement(nextTag);
+				final String type = currentTag.getAttribute("type");
 				if (packetType == PACKET_IQ
 						&& "jingle".equals(child.getName())
 						&& ("set".equalsIgnoreCase(type) || "get"
@@ -432,9 +429,9 @@ public class XmppConnection implements Runnable {
 		return element;
 	}
 
-	private void processIq(Tag currentTag) throws XmlPullParserException,
+	private void processIq(final Tag currentTag) throws XmlPullParserException,
 					IOException {
-						IqPacket packet = (IqPacket) processPacket(currentTag, PACKET_IQ);
+						final IqPacket packet = (IqPacket) processPacket(currentTag, PACKET_IQ);
 
 						if (packet.getId() == null) {
 							return; // an iq packet without id is definitely invalid
@@ -461,11 +458,11 @@ public class XmppConnection implements Runnable {
 						}
 	}
 
-	private void processMessage(Tag currentTag) throws XmlPullParserException,
+	private void processMessage(final Tag currentTag) throws XmlPullParserException,
 					IOException {
-						MessagePacket packet = (MessagePacket) processPacket(currentTag,
+						final MessagePacket packet = (MessagePacket) processPacket(currentTag,
 								PACKET_MESSAGE);
-						String id = packet.getAttribute("id");
+						final String id = packet.getAttribute("id");
 						if ((id != null) && (packetCallbacks.containsKey(id))) {
 							if (packetCallbacks.get(id) instanceof OnMessagePacketReceived) {
 								((OnMessagePacketReceived) packetCallbacks.get(id))
@@ -477,11 +474,11 @@ public class XmppConnection implements Runnable {
 						}
 	}
 
-	private void processPresence(Tag currentTag) throws XmlPullParserException,
+	private void processPresence(final Tag currentTag) throws XmlPullParserException,
 					IOException {
 						PresencePacket packet = (PresencePacket) processPacket(currentTag,
 								PACKET_PRESENCE);
-						String id = packet.getAttribute("id");
+						final String id = packet.getAttribute("id");
 						if ((id != null) && (packetCallbacks.containsKey(id))) {
 							if (packetCallbacks.get(id) instanceof OnPresencePacketReceived) {
 								((OnPresencePacketReceived) packetCallbacks.get(id))
@@ -494,7 +491,7 @@ public class XmppConnection implements Runnable {
 	}
 
 	private void sendStartTLS() throws IOException {
-		Tag startTLS = Tag.empty("starttls");
+		final Tag startTLS = Tag.empty("starttls");
 		startTLS.setAttribute("xmlns", "urn:ietf:params:xml:ns:xmpp-tls");
 		tagWriter.writeTag(startTLS);
 	}
@@ -512,11 +509,11 @@ public class XmppConnection implements Runnable {
 					IOException {
 						tagReader.readTag();
 						try {
-							SSLContext sc = SSLContext.getInstance("TLS");
+							final SSLContext sc = SSLContext.getInstance("TLS");
 							sc.init(null,
 									new X509TrustManager[]{this.mXmppConnectionService.getMemorizingTrustManager()},
 									mXmppConnectionService.getRNG());
-							SSLSocketFactory factory = sc.getSocketFactory();
+							final SSLSocketFactory factory = sc.getSocketFactory();
 
 							if (factory == null) {
 								throw new IOException("SSLSocketFactory was null");
@@ -541,7 +538,7 @@ public class XmppConnection implements Runnable {
 							if (enableLegacySSL()) {
 								supportProtocols = sslSocket.getSupportedProtocols();
 							} else {
-								final List<String> supportedProtocols = new LinkedList<>(
+								final Collection<String> supportedProtocols = new LinkedList<>(
 										Arrays.asList(sslSocket.getSupportedProtocols()));
 								supportedProtocols.remove("SSLv3");
 								supportProtocols = new String[supportedProtocols.size()];
@@ -549,13 +546,13 @@ public class XmppConnection implements Runnable {
 							}
 							sslSocket.setEnabledProtocols(supportProtocols);
 
-                            if (verifier != null
-                                    && !verifier.verify(account.getServer().getDomainpart(),
-                                    sslSocket.getSession())) {
+							if (verifier != null
+									&& !verifier.verify(account.getServer().getDomainpart(),
+										sslSocket.getSession())) {
 								Log.d(Config.LOGTAG,account.getJid().toBareJid()+": TLS certificate verification failed");
 								disconnect(true);
 								changeStatus(Account.State.SECURITY_ERROR);
-                            }
+									}
 							tagReader.setInputStream(sslSocket.getInputStream());
 							tagWriter.setOutputStream(sslSocket.getOutputStream());
 							sendStartStream();
@@ -569,7 +566,7 @@ public class XmppConnection implements Runnable {
 						}
 	}
 
-	private void processStreamFeatures(Tag currentTag)
+	private void processStreamFeatures(final Tag currentTag)
 		throws XmlPullParserException, IOException {
 		this.streamFeatures = tagReader.readElement(currentTag);
 		if (this.streamFeatures.hasChild("starttls") && !enabledEncryption) {
@@ -605,7 +602,7 @@ public class XmppConnection implements Runnable {
 							"). Possible downgrade attack?");
 					disconnect(true);
 					changeStatus(Account.State.SECURITY_ERROR);
-				}
+						}
 			} catch (final JSONException e) {
 				Log.d(Config.LOGTAG, "Parse error while checking pinned auth mechanism");
 			}
@@ -618,7 +615,7 @@ public class XmppConnection implements Runnable {
 		} else if (this.streamFeatures.hasChild("sm", "urn:xmpp:sm:"
 					+ smVersion)
 				&& streamId != null) {
-			ResumePacket resume = new ResumePacket(this.streamId,
+			final ResumePacket resume = new ResumePacket(this.streamId,
 					stanzasReceived, smVersion);
 			this.tagWriter.writeStanzaAsync(resume);
 		} else if (this.streamFeatures.hasChild("bind") && shouldBind) {
@@ -629,45 +626,44 @@ public class XmppConnection implements Runnable {
 		}
 	}
 
-	private List<String> extractMechanisms(Element stream) {
-		ArrayList<String> mechanisms = new ArrayList<>(stream
+	private List<String> extractMechanisms(final Element stream) {
+		final ArrayList<String> mechanisms = new ArrayList<>(stream
 				.getChildren().size());
-		for (Element child : stream.getChildren()) {
+		for (final Element child : stream.getChildren()) {
 			mechanisms.add(child.getContent());
 		}
 		return mechanisms;
 	}
 
 	private void sendRegistryRequest() {
-		IqPacket register = new IqPacket(IqPacket.TYPE_GET);
+		final IqPacket register = new IqPacket(IqPacket.TYPE_GET);
 		register.query("jabber:iq:register");
 		register.setTo(account.getServer());
 		sendIqPacket(register, new OnIqPacketReceived() {
 
 			@Override
-			public void onIqPacketReceived(Account account, IqPacket packet) {
-				Element instructions = packet.query().findChild("instructions");
+			public void onIqPacketReceived(final Account account, final IqPacket packet) {
+				final Element instructions = packet.query().findChild("instructions");
 				if (packet.query().hasChild("username")
 						&& (packet.query().hasChild("password"))) {
-					IqPacket register = new IqPacket(IqPacket.TYPE_SET);
-					Element username = new Element("username")
-							.setContent(account.getUsername());
-					Element password = new Element("password")
-							.setContent(account.getPassword());
+					final IqPacket register = new IqPacket(IqPacket.TYPE_SET);
+					final Element username = new Element("username")
+						.setContent(account.getUsername());
+					final Element password = new Element("password")
+						.setContent(account.getPassword());
 					register.query("jabber:iq:register").addChild(username);
 					register.query().addChild(password);
 					sendIqPacket(register, new OnIqPacketReceived() {
 
 						@Override
-						public void onIqPacketReceived(Account account,
-													   IqPacket packet) {
+						public void onIqPacketReceived(final Account account, final IqPacket packet) {
 							if (packet.getType() == IqPacket.TYPE_RESULT) {
 								account.setOption(Account.OPTION_REGISTER,
 										false);
 								changeStatus(Account.State.REGISTRATION_SUCCESSFUL);
 							} else if (packet.hasChild("error")
 									&& (packet.findChild("error")
-									.hasChild("conflict"))) {
+										.hasChild("conflict"))) {
 								changeStatus(Account.State.REGISTRATION_CONFLICT);
 							} else {
 								changeStatus(Account.State.REGISTRATION_FAILED);
@@ -687,14 +683,14 @@ public class XmppConnection implements Runnable {
 		});
 	}
 
-	private void sendBindRequest() throws IOException {
-		IqPacket iq = new IqPacket(IqPacket.TYPE_SET);
+	private void sendBindRequest() {
+		final IqPacket iq = new IqPacket(IqPacket.TYPE_SET);
 		iq.addChild("bind", "urn:ietf:params:xml:ns:xmpp-bind")
 			.addChild("resource").setContent(account.getResource());
 		this.sendUnboundIqPacket(iq, new OnIqPacketReceived() {
 			@Override
-			public void onIqPacketReceived(Account account, IqPacket packet) {
-				Element bind = packet.findChild("bind");
+			public void onIqPacketReceived(final Account account, final IqPacket packet) {
+				final Element bind = packet.findChild("bind");
 				if (bind != null) {
 					final Element jid = bind.findChild("jid");
 					if (jid != null && jid.getContent() != null) {
@@ -705,14 +701,14 @@ public class XmppConnection implements Runnable {
 						}
 						if (streamFeatures.hasChild("sm", "urn:xmpp:sm:3")) {
 							smVersion = 3;
-							EnablePacket enable = new EnablePacket(smVersion);
+							final EnablePacket enable = new EnablePacket(smVersion);
 							tagWriter.writeStanzaAsync(enable);
 							stanzasSent = 0;
 							messageReceipts.clear();
 						} else if (streamFeatures.hasChild("sm",
-								"urn:xmpp:sm:2")) {
+									"urn:xmpp:sm:2")) {
 							smVersion = 2;
-							EnablePacket enable = new EnablePacket(smVersion);
+							final EnablePacket enable = new EnablePacket(smVersion);
 							tagWriter.writeStanzaAsync(enable);
 							stanzasSent = 0;
 							messageReceipts.clear();
@@ -736,7 +732,7 @@ public class XmppConnection implements Runnable {
 		if (this.streamFeatures.hasChild("session")) {
 			Log.d(Config.LOGTAG, account.getJid().toBareJid()
 					+ ": sending deprecated session");
-			IqPacket startSession = new IqPacket(IqPacket.TYPE_SET);
+			final IqPacket startSession = new IqPacket(IqPacket.TYPE_SET);
 			startSession.addChild("session",
 					"urn:ietf:params:xml:ns:xmpp-session");
 			this.sendUnboundIqPacket(startSession, null);
@@ -755,10 +751,10 @@ public class XmppConnection implements Runnable {
 			this.sendIqPacket(iq, new OnIqPacketReceived() {
 
 				@Override
-				public void onIqPacketReceived(Account account, IqPacket packet) {
+				public void onIqPacketReceived(final Account account, final IqPacket packet) {
 					final List<Element> elements = packet.query().getChildren();
 					final List<String> features = new ArrayList<>();
-					for (Element element : elements) {
+					for (final Element element : elements) {
 						if (element.getName().equals("identity")) {
 							if ("irc".equals(element.getAttribute("type"))) {
 								//add fake feature to not confuse irc and real muc
@@ -772,7 +768,7 @@ public class XmppConnection implements Runnable {
 
 					if (account.getServer().equals(server.toDomainJid())) {
 						enableAdvancedStreamFeatures();
-						for(OnAdvancedStreamFeaturesLoaded listener : advancedStreamFeaturesLoadedListeners) {
+						for (final OnAdvancedStreamFeaturesLoaded listener : advancedStreamFeaturesLoadedListeners) {
 							listener.onAdvancedStreamFeaturesAvailable(account);
 						}
 					}
@@ -787,6 +783,10 @@ public class XmppConnection implements Runnable {
 				sendEnableCarbons();
 			}
 		}
+		if (getFeatures().blocking()) {
+			Log.d(Config.LOGTAG, "Requesting block list");
+			this.sendIqPacket(getIqGenerator().generateGetBlockList(), mXmppConnectionService.getIqParser());
+		}
 	}
 
 	private void sendServiceDiscoveryItems(final Jid server) {
@@ -796,9 +796,9 @@ public class XmppConnection implements Runnable {
 		this.sendIqPacket(iq, new OnIqPacketReceived() {
 
 			@Override
-			public void onIqPacketReceived(Account account, IqPacket packet) {
-				List<Element> elements = packet.query().getChildren();
-				for (Element element : elements) {
+			public void onIqPacketReceived(final Account account, final IqPacket packet) {
+				final List<Element> elements = packet.query().getChildren();
+				for (final Element element : elements) {
 					if (element.getName().equals("item")) {
 						final Jid jid = element.getAttributeAsJid("jid");
 						if (jid != null && !jid.equals(account.getServer())) {
@@ -811,12 +811,12 @@ public class XmppConnection implements Runnable {
 	}
 
 	private void sendEnableCarbons() {
-		IqPacket iq = new IqPacket(IqPacket.TYPE_SET);
+		final IqPacket iq = new IqPacket(IqPacket.TYPE_SET);
 		iq.addChild("enable", "urn:xmpp:carbons:2");
 		this.sendIqPacket(iq, new OnIqPacketReceived() {
 
 			@Override
-			public void onIqPacketReceived(Account account, IqPacket packet) {
+			public void onIqPacketReceived(final Account account, final IqPacket packet) {
 				if (!packet.hasChild("error")) {
 					Log.d(Config.LOGTAG, account.getJid().toBareJid()
 							+ ": successfully enabled carbons");
@@ -829,20 +829,20 @@ public class XmppConnection implements Runnable {
 		});
 	}
 
-	private void processStreamError(Tag currentTag)
+	private void processStreamError(final Tag currentTag)
 		throws XmlPullParserException, IOException {
-		Element streamError = tagReader.readElement(currentTag);
+		final Element streamError = tagReader.readElement(currentTag);
 		if (streamError != null && streamError.hasChild("conflict")) {
 			final String resource = account.getResource().split("\\.")[0];
 			account.setResource(resource + "." + nextRandomId());
 			Log.d(Config.LOGTAG,
 					account.getJid().toBareJid() + ": switching resource due to conflict ("
-							+ account.getResource() + ")");
+					+ account.getResource() + ")");
 		}
 	}
 
 	private void sendStartStream() throws IOException {
-		Tag stream = Tag.start("stream:stream");
+		final Tag stream = Tag.start("stream:stream");
 		stream.setAttribute("from", account.getJid().toBareJid().toString());
 		stream.setAttribute("to", account.getServer().toString());
 		stream.setAttribute("version", "1.0");
@@ -856,33 +856,32 @@ public class XmppConnection implements Runnable {
 		return new BigInteger(50, mXmppConnectionService.getRNG()).toString(32);
 	}
 
-	public void sendIqPacket(IqPacket packet, OnIqPacketReceived callback) {
+	public void sendIqPacket(final IqPacket packet, final PacketReceived callback) {
 		if (packet.getId() == null) {
-			String id = nextRandomId();
+			final String id = nextRandomId();
 			packet.setAttribute("id", id);
 		}
 		packet.setFrom(account.getJid());
 		this.sendPacket(packet, callback);
 	}
 
-	public void sendUnboundIqPacket(IqPacket packet, OnIqPacketReceived callback) {
+	public void sendUnboundIqPacket(final IqPacket packet, final PacketReceived callback) {
 		if (packet.getId() == null) {
-			String id = nextRandomId();
+			final String id = nextRandomId();
 			packet.setAttribute("id", id);
 		}
 		this.sendPacket(packet, callback);
 	}
 
-	public void sendMessagePacket(MessagePacket packet) {
+	public void sendMessagePacket(final MessagePacket packet) {
 		this.sendPacket(packet, null);
 	}
 
-	public void sendPresencePacket(PresencePacket packet) {
+	public void sendPresencePacket(final PresencePacket packet) {
 		this.sendPacket(packet, null);
 	}
 
-	private synchronized void sendPacket(final AbstractStanza packet,
-			PacketReceived callback) {
+	private synchronized void sendPacket(final AbstractStanza packet, final PacketReceived callback) {
 		if (packet.getName().equals("iq") || packet.getName().equals("message")
 				|| packet.getName().equals("presence")) {
 			++stanzasSent;
@@ -907,7 +906,7 @@ public class XmppConnection implements Runnable {
 		if (streamFeatures.hasChild("sm")) {
 			tagWriter.writeStanzaAsync(new RequestPacket(smVersion));
 		} else {
-			IqPacket iq = new IqPacket(IqPacket.TYPE_GET);
+			final IqPacket iq = new IqPacket(IqPacket.TYPE_GET);
 			iq.setFrom(account.getJid());
 			iq.addChild("ping", "urn:xmpp:ping");
 			this.sendIqPacket(iq, null);
@@ -916,44 +915,44 @@ public class XmppConnection implements Runnable {
 	}
 
 	public void setOnMessagePacketReceivedListener(
-			OnMessagePacketReceived listener) {
+			final OnMessagePacketReceived listener) {
 		this.messageListener = listener;
 			}
 
 	public void setOnUnregisteredIqPacketReceivedListener(
-			OnIqPacketReceived listener) {
+			final OnIqPacketReceived listener) {
 		this.unregisteredIqListener = listener;
 			}
 
 	public void setOnPresencePacketReceivedListener(
-			OnPresencePacketReceived listener) {
+			final OnPresencePacketReceived listener) {
 		this.presenceListener = listener;
 			}
 
 	public void setOnJinglePacketReceivedListener(
-			OnJinglePacketReceived listener) {
+			final OnJinglePacketReceived listener) {
 		this.jingleListener = listener;
 			}
 
-	public void setOnStatusChangedListener(OnStatusChanged listener) {
+	public void setOnStatusChangedListener(final OnStatusChanged listener) {
 		this.statusListener = listener;
 	}
 
-	public void setOnBindListener(OnBindListener listener) {
+	public void setOnBindListener(final OnBindListener listener) {
 		this.bindListener = listener;
 	}
 
-	public void setOnMessageAcknowledgeListener(OnMessageAcknowledged listener) {
+	public void setOnMessageAcknowledgeListener(final OnMessageAcknowledged listener) {
 		this.acknowledgedListener = listener;
 	}
 
-	public void addOnAdvancedStreamFeaturesAvailableListener(OnAdvancedStreamFeaturesLoaded listener) {
+	public void addOnAdvancedStreamFeaturesAvailableListener(final OnAdvancedStreamFeaturesLoaded listener) {
 		if (!this.advancedStreamFeaturesLoadedListeners.contains(listener)) {
 			this.advancedStreamFeaturesLoadedListeners.add(listener);
 		}
 	}
 
-	public void disconnect(boolean force) {
+	public void disconnect(final boolean force) {
 		Log.d(Config.LOGTAG, account.getJid().toBareJid() + ": disconnecting");
 		try {
 			if (force) {
@@ -973,23 +972,23 @@ public class XmppConnection implements Runnable {
 							}
 							tagWriter.writeTag(Tag.end("stream:stream"));
 							socket.close();
-						} catch (IOException e) {
+						} catch (final IOException e) {
 							Log.d(Config.LOGTAG,
 									"io exception during disconnect");
-						} catch (InterruptedException e) {
+						} catch (final InterruptedException e) {
 							Log.d(Config.LOGTAG, "interrupted");
 						}
 					}
 				}
 			}).start();
-		} catch (IOException e) {
+		} catch (final IOException e) {
 			Log.d(Config.LOGTAG, "io exception during disconnect");
 		}
 	}
 
-	public List<String> findDiscoItemsByFeature(String feature) {
+	public List<String> findDiscoItemsByFeature(final String feature) {
 		final List<String> items = new ArrayList<>();
-		for (Entry<String, List<String>> cursor : disco.entrySet()) {
+		for (final Entry<String, List<String>> cursor : disco.entrySet()) {
 			if (cursor.getValue().contains(feature)) {
 				items.add(cursor.getKey());
 			}
@@ -997,8 +996,8 @@ public class XmppConnection implements Runnable {
 		return items;
 	}
 
-	public String findDiscoItemByFeature(String feature) {
-		List<String> items = findDiscoItemsByFeature(feature);
+	public String findDiscoItemByFeature(final String feature) {
+		final List<String> items = findDiscoItemsByFeature(feature);
 		if (items.size() >= 1) {
 			return items.get(0);
 		}
@@ -1010,8 +1009,7 @@ public class XmppConnection implements Runnable {
 	}
 
 	public String getMucServer() {
-		final List<String> items = new ArrayList<>();
-		for (Entry<String, List<String>> cursor : disco.entrySet()) {
+		for (final Entry<String, List<String>> cursor : disco.entrySet()) {
 			final List<String> value = cursor.getValue();
 			if (value.contains("http://jabber.org/protocol/muc") && !value.contains("jabber:iq:gateway") && !value.contains("siacs:no:muc")) {
 				return cursor.getKey();
@@ -1021,8 +1019,8 @@ public class XmppConnection implements Runnable {
 	}
 
 	public int getTimeToNextAttempt() {
-		int interval = (int) (25 * Math.pow(1.5, attempt));
-		int secondsSinceLast = (int) ((SystemClock.elapsedRealtime() - this.lastConnect) / 1000);
+		final int interval = (int) (25 * Math.pow(1.5, attempt));
+		final int secondsSinceLast = (int) ((SystemClock.elapsedRealtime() - this.lastConnect) / 1000);
 		return interval - secondsSinceLast;
 	}
 
@@ -1035,7 +1033,7 @@ public class XmppConnection implements Runnable {
 	}
 
 	public long getLastSessionEstablished() {
-		long diff;
+		final long diff;
 		if (this.lastSessionStarted == 0) {
 			diff = SystemClock.elapsedRealtime() - this.lastConnect;
 		} else {
@@ -1067,7 +1065,7 @@ public class XmppConnection implements Runnable {
 	public class Features {
 		XmppConnection connection;
 
-		public Features(XmppConnection connection) {
+		public Features(final XmppConnection connection) {
 			this.connection = connection;
 		}
 
@@ -1080,6 +1078,10 @@ public class XmppConnection implements Runnable {
 			return hasDiscoFeature(account.getServer(), "urn:xmpp:carbons:2");
 		}
 
+		public boolean blocking() {
+			return hasDiscoFeature(account.getServer(), Xmlns.BLOCKING);
+		}
+
 		public boolean sm() {
 			return streamId != null;
 		}
@@ -1110,4 +1112,8 @@ public class XmppConnection implements Runnable {
 				.findDiscoItemByFeature("http://jabber.org/protocol/bytestreams") != null;
 		}
 	}
+
+	private IqGenerator getIqGenerator() {
+		return mXmppConnectionService.getIqGenerator();
+	}
 }
diff --git a/src/main/java/eu/siacs/conversations/xmpp/jid/Jid.java b/src/main/java/eu/siacs/conversations/xmpp/jid/Jid.java
index c40fa0b6..a35ea37c 100644
--- a/src/main/java/eu/siacs/conversations/xmpp/jid/Jid.java
+++ b/src/main/java/eu/siacs/conversations/xmpp/jid/Jid.java
@@ -32,7 +32,7 @@ public final class Jid {
 		return resourcepart;
 	}
 
-	public static Jid fromSessionID(SessionID id) throws InvalidJidException{
+	public static Jid fromSessionID(final SessionID id) throws InvalidJidException{
 		if (id.getUserID().isEmpty()) {
 			return Jid.fromString(id.getAccountID());
 		} else {
@@ -190,4 +190,8 @@ public final class Jid {
 	public boolean isBareJid() {
 		return this.resourcepart.isEmpty();
 	}
+
+	public boolean isDomainJid() {
+		return !this.hasLocalpart();
+	}
 }
diff --git a/src/main/java/eu/siacs/conversations/xmpp/stanzas/IqPacket.java b/src/main/java/eu/siacs/conversations/xmpp/stanzas/IqPacket.java
index 9df05e67..9eff4cbf 100644
--- a/src/main/java/eu/siacs/conversations/xmpp/stanzas/IqPacket.java
+++ b/src/main/java/eu/siacs/conversations/xmpp/stanzas/IqPacket.java
@@ -9,27 +9,27 @@ public class IqPacket extends AbstractStanza {
 	public static final int TYPE_RESULT = 1;
 	public static final int TYPE_GET = 2;
 
-	private IqPacket(String name) {
+	private IqPacket(final String name) {
 		super(name);
 	}
 
-	public IqPacket(int type) {
+	public IqPacket(final int type) {
 		super("iq");
 		switch (type) {
-		case TYPE_SET:
-			this.setAttribute("type", "set");
-			break;
-		case TYPE_GET:
-			this.setAttribute("type", "get");
-			break;
-		case TYPE_RESULT:
-			this.setAttribute("type", "result");
-			break;
-		case TYPE_ERROR:
-			this.setAttribute("type", "error");
-			break;
-		default:
-			break;
+			case TYPE_SET:
+				this.setAttribute("type", "set");
+				break;
+			case TYPE_GET:
+				this.setAttribute("type", "get");
+				break;
+			case TYPE_RESULT:
+				this.setAttribute("type", "result");
+				break;
+			case TYPE_ERROR:
+				this.setAttribute("type", "error");
+				break;
+			default:
+				break;
 		}
 	}
 
@@ -45,29 +45,30 @@ public class IqPacket extends AbstractStanza {
 		return query;
 	}
 
-	public Element query(String xmlns) {
-		Element query = query();
+	public Element query(final String xmlns) {
+		final Element query = query();
 		query.setAttribute("xmlns", xmlns);
 		return query();
 	}
 
 	public int getType() {
-		String type = getAttribute("type");
-		if ("error".equals(type)) {
-			return TYPE_ERROR;
-		} else if ("result".equals(type)) {
-			return TYPE_RESULT;
-		} else if ("set".equals(type)) {
-			return TYPE_SET;
-		} else if ("get".equals(type)) {
-			return TYPE_GET;
-		} else {
-			return 1000;
+		final String type = getAttribute("type");
+		switch (type) {
+			case "error":
+				return TYPE_ERROR;
+			case "result":
+				return TYPE_RESULT;
+			case "set":
+				return TYPE_SET;
+			case "get":
+				return TYPE_GET;
+			default:
+				return 1000;
 		}
 	}
 
-	public IqPacket generateRespone(int type) {
-		IqPacket packet = new IqPacket(type);
+	public IqPacket generateRespone(final int type) {
+		final IqPacket packet = new IqPacket(type);
 		packet.setTo(this.getFrom());
 		packet.setId(this.getId());
 		return packet;
diff --git a/src/main/res/menu/contact_context.xml b/src/main/res/menu/contact_context.xml
index 11ac7d7c..223c7ece 100644
--- a/src/main/res/menu/contact_context.xml
+++ b/src/main/res/menu/contact_context.xml
@@ -8,6 +8,9 @@
         android:id="@+id/context_contact_details"
         android:title="@string/view_contact_details"/>
     <item
+        android:id="@+id/context_contact_block_unblock"
+        android:title="@string/block_contact"/>
+    <item
         android:id="@+id/context_delete_contact"
         android:title="@string/delete_contact"/>
 
diff --git a/src/main/res/menu/conversations.xml b/src/main/res/menu/conversations.xml
index d68c1436..6c22ed18 100644
--- a/src/main/res/menu/conversations.xml
+++ b/src/main/res/menu/conversations.xml
@@ -57,6 +57,18 @@
         android:title="@string/enable_notifications"/>
 
     <item
+        android:id="@+id/action_block"
+        android:orderInCategory="72"
+        android:showAsAction="never"
+        android:title="@string/action_block_contact"/>
+
+    <item
+        android:id="@+id/action_unblock"
+        android:orderInCategory="73"
+        android:showAsAction="never"
+        android:title="@string/action_unblock_contact"/>
+
+    <item
         android:id="@+id/action_accounts"
         android:orderInCategory="90"
         android:showAsAction="never"
diff --git a/src/main/res/menu/editaccount.xml b/src/main/res/menu/editaccount.xml
index 2301caf0..5d10901e 100644
--- a/src/main/res/menu/editaccount.xml
+++ b/src/main/res/menu/editaccount.xml
@@ -4,5 +4,9 @@
         android:id="@+id/action_show_qr_code"
         android:title="@string/show_qr_code"
         android:showAsAction="never" />
+    <item
+        android:id="@+id/action_show_block_list"
+        android:title="@string/show_block_list"
+        android:showAsAction="never" />
 
 </menu>
\ No newline at end of file
diff --git a/src/main/res/values/strings.xml b/src/main/res/values/strings.xml
index ec761d6e..ba3051b2 100644
--- a/src/main/res/values/strings.xml
+++ b/src/main/res/values/strings.xml
@@ -13,6 +13,10 @@
     <string name="action_edit_contact">Edit name</string>
     <string name="action_add_phone_book">Add to phone book</string>
     <string name="action_delete_contact">Delete from roster</string>
+    <string name="action_block_contact">Block contact</string>
+    <string name="action_unblock_contact">Unblock contact</string>
+    <string name="action_block_domain">Block domain</string>
+    <string name="action_unblock_domain">Unblock domain</string>
     <string name="title_activity_manage_accounts">Manage Accounts</string>
     <string name="title_activity_settings">Settings</string>
     <string name="title_activity_conference_details">Conference Details</string>
@@ -21,6 +25,7 @@
     <string name="title_activity_sharewith">Share with Conversation</string>
     <string name="title_activity_start_conversation">Start Conversation</string>
     <string name="title_activity_choose_contact">Choose contact</string>
+    <string name="title_activity_block_list">Block list</string>
     <string name="just_now">just now</string>
     <string name="minute_ago">1 min ago</string>
     <string name="minutes_ago">%d mins ago</string>
@@ -34,6 +39,11 @@
     <string name="participant">Participant</string>
     <string name="visitor">Visitor</string>
     <string name="remove_contact_text">Would you like to remove %s from your roster? The conversation associated with this contact will not be removed.</string>
+    <string name="block_contact_text">Would you like to block %s from sending you messages?</string>
+    <string name="unblock_contact_text">Would you like to unblock %s and allow them to send you messages?</string>
+    <string name="block_domain_text">Block all contacts from %s?</string>
+    <string name="unblock_domain_text">Unblock all contacts from %s?</string>
+    <string name="contact_blocked">Contact blocked</string>
     <string name="remove_bookmark_text">Would you like to remove %s as a bookmark? The conversation associated with this bookmark will not be removed.</string>
     <string name="register_account">Register new account on server</string>
     <string name="share_with">Share with</string>
@@ -45,6 +55,8 @@
     <string name="add">Add</string>
     <string name="edit">Edit</string>
     <string name="delete">Delete</string>
+    <string name="block">Block</string>
+    <string name="unblock">Unblock</string>
     <string name="save">Save</string>
     <string name="ok">OK</string>
     <string name="crash_report_title">Conversations has crashed</string>
@@ -202,6 +214,8 @@
     <string name="join_conference">Join Conference</string>
     <string name="delete_contact">Delete Contact</string>
     <string name="view_contact_details">View contact details</string>
+    <string name="block_contact">Block contact</string>
+    <string name="unblock_contact">Unblock contact</string>
     <string name="create">Create</string>
     <string name="contact_already_exists">The contact already exists</string>
     <string name="join">Join</string>
@@ -318,6 +332,7 @@
     <string name="image_transmission_failed">Image transmission failed</string>
     <string name="scan_qr_code">Scan QR code</string>
     <string name="show_qr_code">Show QR code</string>
+    <string name="show_block_list">Show block list</string>
     <string name="account_details">Account details</string>
     <string name="verify_otr">Verify OTR</string>
     <string name="remote_fingerprint">Remote Fingerprint</string>