diff --git a/src/categories.js b/src/categories.js
index 01c831c5af..479bd29d41 100644
--- a/src/categories.js
+++ b/src/categories.js
@@ -74,6 +74,7 @@ var	RDB = require('./redis.js'),
 						categoryData.moderator_block_class = results[1].length > 0 ? '' : 'none';
 						categoryData.moderators = results[1];
 						categoryData.active_users = results[2];
+						categoryData.show_sidebar = categoryData.topics.length > 0 ? 'show':'hidden';
 						callback(null, categoryData);
 					});
 				}
@@ -234,6 +235,26 @@ var	RDB = require('./redis.js'),
 		});
 	}
 
+	Categories.moveActiveUsers = function(tid, oldCid, cid, callback) {
+		topics.getUids(tid, function(err, uids) {
+			if(!err && uids) {
+				function updateUser(uid) {
+					Categories.addActiveUser(cid, uid);
+					Categories.isUserActiveIn(oldCid, uid, function(err, active) {
+
+						if(!err && !active) {
+							Categories.removeActiveUser(oldCid, uid);
+						}
+					});
+				}
+
+				for(var i=0; i<uids.length; ++i) {
+					updateUser(uids[i]);
+				}
+			}
+		});
+	}
+
 	Categories.getCategoryData = function(cid, callback) {
 		RDB.exists('category:' + cid, function(err, exists) {
 			if (exists) RDB.hgetall('category:' + cid, callback);
@@ -299,5 +320,58 @@ var	RDB = require('./redis.js'),
 
 	};
 
+	Categories.isUserActiveIn = function(cid, uid, callback) {
+
+		RDB.lrange('uid:' + uid + ':posts', 0, -1, function(err, pids) {
+			if(err)
+				return callback(err, null);
+
+			function getPostCategory(pid, callback) {
+				posts.getPostField(pid, 'tid', function(tid) {
+
+					topics.getTopicField(tid, 'cid', function(err, postCid) {
+						if(err)
+							return callback(err, null);
+
+						return callback(null, postCid);
+					});
+				});
+			}
+
+			var index = 0,
+				active = false;
+
+			async.whilst(
+				function() {
+					return active === false && index < pids.length;
+				},
+				function(callback) {
+					getPostCategory(pids[index], function(err, postCid) {
+						if(err)
+							return callback(err);
+						if(postCid === cid)
+							active = true;
+						++index;
+						callback(null);
+					})
+				},
+				function(err) {
+					if(err)
+						return callback(err, null);
+
+					callback(null, active);
+				}
+			);
+		});
+	}
+
+	Categories.addActiveUser = function(cid, uid) {
+		RDB.sadd('cid:' + cid + ':active_users', uid);
+	}
+
+	Categories.removeActiveUser = function(cid, uid) {
+		RDB.srem('cid:' + cid + ':active_users', uid);
+	}
+
 }(exports));
 
diff --git a/src/plugins.js b/src/plugins.js
index 2c1acf8739..4a4772ff57 100644
--- a/src/plugins.js
+++ b/src/plugins.js
@@ -80,7 +80,7 @@ var	fs = require('fs'),
 				hookList = this.loadedHooks[hook];
 
 			if (hookList && Array.isArray(hookList)) {
-				if (global.env === 'development') winston.info('[plugins] Firing hook: \'' + hook + '\'');
+				//if (global.env === 'development') winston.info('[plugins] Firing hook: \'' + hook + '\'');
 				var	hookType = hook.split(':')[0];
 				switch(hookType) {
 					case 'filter':
diff --git a/src/posts.js b/src/posts.js
index 5ada90d6e5..8f59d8c5a0 100644
--- a/src/posts.js
+++ b/src/posts.js
@@ -310,7 +310,7 @@ var	RDB = require('./redis.js'),
 									RDB.spop('cid:' + cid + ':active_users');
 								}
 
-								RDB.sadd('cid:' + cid + ':active_users', uid);
+								categories.addActiveUser(cid, uid);
 							});
 						});
 
diff --git a/src/threadTools.js b/src/threadTools.js
index a20323eb1f..5a6b9f5e0d 100644
--- a/src/threadTools.js
+++ b/src/threadTools.js
@@ -199,12 +199,19 @@ var	RDB = require('./redis.js'),
 						}
 					});
 
+					categories.moveActiveUsers(tid, oldCid, cid, function(err, data) {
+						if(err) {
+							winston.err(err);
+						}
+					});
+
 					categories.incrementCategoryFieldBy(oldCid, 'topic_count', -1);
 					categories.incrementCategoryFieldBy(cid, 'topic_count', 1);
 
 					socket.emit('api:topic.move', {
 						status: 'ok'
 					});
+
 					io.sockets.in('topic_' + tid).emit('event:topic_moved', {
 						tid: tid
 					});
diff --git a/src/topics.js b/src/topics.js
index 10cf449541..20687f1ecd 100644
--- a/src/topics.js
+++ b/src/topics.js
@@ -722,6 +722,28 @@ marked.setOptions({
 		RDB.lrange('tid:' + tid + ':posts', 0, -1, callback);
 	}
 
+	Topics.getUids = function(tid, callback) {
+		var uids = {};
+		Topics.getPids(tid, function(err, pids) {
+
+			function getUid(pid, next) {
+				posts.getPostField(pid, 'uid', function(uid) {
+					if(err)
+						return next(err);
+					uids[uid] = 1;
+					next(null);
+				});
+			}
+
+			async.each(pids, getUid, function(err) {
+				if(err)
+					return callback(err, null);
+
+				callback(null, Object.keys(uids));
+			});
+		});
+	}
+
 	Topics.delete = function(tid) {
 		Topics.setTopicField(tid, 'deleted', 1);
 		RDB.zrem('topics:recent', tid);