diff --git a/angular_app/js/app.js b/angular_app/js/app.js
index e15981c..2929fb8 100644
--- a/angular_app/js/app.js
+++ b/angular_app/js/app.js
@@ -28,8 +28,10 @@ var eventManApp = angular.module('eventManApp', [
 
 
 /* Add some utilities to the global scope. */
-eventManApp.run(['$rootScope', '$state', '$stateParams',
-    function($rootScope, $state, $stateParams) {
+eventManApp.run(['$rootScope', '$state', '$stateParams', '$log',
+    function($rootScope, $state, $stateParams, $log) {
+        $rootScope.app_uuid = guid();
+        $log.debug('App UUID: ' + $rootScope.app_uuid);
         $rootScope.$state = $state;
         $rootScope.$stateParams = $stateParams;
     }]
diff --git a/angular_app/js/controllers.js b/angular_app/js/controllers.js
index 1e363bb..2a44349 100644
--- a/angular_app/js/controllers.js
+++ b/angular_app/js/controllers.js
@@ -96,8 +96,8 @@ eventManControllers.controller('EventsListCtrl', ['$scope', 'Event', '$modal', '
 );
 
 
-eventManControllers.controller('EventDetailsCtrl', ['$scope', '$state', 'Event', 'Person', 'EventUpdates', '$stateParams', 'Setting', '$log', '$translate',
-    function ($scope, $state, Event, Person, EventUpdates, $stateParams, Setting, $log, $translate) {
+eventManControllers.controller('EventDetailsCtrl', ['$scope', '$state', 'Event', 'Person', 'EventUpdates', '$stateParams', 'Setting', '$log', '$translate', '$rootScope',
+    function ($scope, $state, Event, Person, EventUpdates, $stateParams, Setting, $log, $translate, $rootScope) {
         $scope.personsOrder = ["name", "surname"];
         $scope.countAttendees = 0;
         $scope.message = {};
@@ -127,7 +127,11 @@ eventManControllers.controller('EventDetailsCtrl', ['$scope', '$state', 'Event',
                             return;
                         }
                         var data = $scope.EventUpdates.data.update;
-                        $log.debug('received ' + data.action + ' action from websocket');
+                        $log.debug('received ' + data.action + ' action from websocket source ' + data.uuid);
+                        if ($rootScope.app_uuid == data.uuid) {
+                            $log.debug('do not process our own message');
+                            return false;
+                        }
                         if (!$scope.event.persons) {
                             $scope.event.persons = [];
                         }
diff --git a/angular_app/js/services.js b/angular_app/js/services.js
index e4c12c6..f5ac7ab 100644
--- a/angular_app/js/services.js
+++ b/angular_app/js/services.js
@@ -4,8 +4,8 @@
 var eventManServices = angular.module('eventManServices', ['ngResource']);
 
 
-eventManServices.factory('Event', ['$resource',
-    function($resource) {
+eventManServices.factory('Event', ['$resource', '$rootScope',
+    function($resource, $rootScope) {
         return $resource('events/:id', {id: '@_id', person_id: '@person_id'}, {
 
             all: {
@@ -43,6 +43,7 @@ eventManServices.factory('Event', ['$resource',
                 method: 'PUT',
                 isArray: false,
                 url: 'events/:id/persons/:person_id',
+                params: {uuid: $rootScope.app_uuid},
                 transformResponse: function(data, headers) {
                     return angular.fromJson(data);
                 }
@@ -52,6 +53,7 @@ eventManServices.factory('Event', ['$resource',
                 method: 'POST',
                 isArray: false,
                 url: 'events/:id/persons/:person_id',
+                params: {uuid: $rootScope.app_uuid},
                 transformResponse: function(data, headers) {
                     return angular.fromJson(data);
                 }
@@ -61,6 +63,7 @@ eventManServices.factory('Event', ['$resource',
                 method: 'DELETE',
                 isArray: false,
                 url: 'events/:_id/persons/:person_id',
+                params: {uuid: $rootScope.app_uuid},
                 transformResponse: function(data, headers) {
                     return angular.fromJson(data);
                 }
diff --git a/eventman_server.py b/eventman_server.py
index 6348956..92167ff 100755
--- a/eventman_server.py
+++ b/eventman_server.py
@@ -66,6 +66,16 @@ class BaseHandler(tornado.web.RequestHandler):
     arguments = property(lambda self: dict([(k, v[0])
         for k, v in self.request.arguments.iteritems()]))
 
+    # A property to access both the UUID and the clean arguments.
+    @property
+    def uuid_arguments(self):
+        uuid = None
+        arguments = self.arguments
+        if 'uuid' in arguments:
+            uuid = arguments['uuid']
+            del arguments['uuid']
+        return uuid, arguments
+
     _bool_convert = {
         '0': False,
         'n': False,
@@ -400,6 +410,7 @@ class EventsHandler(CollectionHandler):
 
     def handle_post_persons(self, id_, person_id, data):
         # Add a person to the list of persons registered at this event.
+        uuid, arguments = self.uuid_arguments
         self._clean_dict(data)
         data['seq'] = self.get_next_seq('event_%s_persons' % id_)
         data['seq_hex'] = '%06X' % data['seq']
@@ -407,7 +418,7 @@ class EventsHandler(CollectionHandler):
                 {'_id': id_, 'persons.person_id': person_id})
         if '_id' in data:
             del data['_id']
-        ret = {'action': 'add', 'person_id': person_id, 'person': data}
+            ret = {'action': 'add', 'person_id': person_id, 'person': data, 'uuid': uuid}
         if not doc:
             merged, doc = self.db.update('events',
                     {'_id': id_},
@@ -420,7 +431,8 @@ class EventsHandler(CollectionHandler):
     def handle_put_persons(self, id_, person_id, data):
         # Update an existing entry for a person registered at this event.
         self._clean_dict(data)
-        query = dict([('persons.%s' % k, v) for k, v in self.arguments.iteritems()])
+        uuid, arguments = self.uuid_arguments
+        query = dict([('persons.%s' % k, v) for k, v in arguments.iteritems()])
         query['_id'] = id_
         if person_id is not None:
             query['persons.person_id'] = person_id
@@ -452,16 +464,17 @@ class EventsHandler(CollectionHandler):
             if new_person_data.get('attended'):
                 self.run_triggers('attends', stdin_data=stdin_data, env=env)
 
-        ret = {'action': 'update', 'person_id': person_id, 'person': new_person_data}
+        ret = {'action': 'update', 'person_id': person_id, 'person': new_person_data, 'uuid': uuid}
         if old_person_data != new_person_data:
             self.send_ws_message('event/%s/updates' % id_, json.dumps(ret))
         return ret
 
     def handle_delete_persons(self, id_, person_id):
         # Remove a specific person from the list of persons registered at this event.
+        uuid, arguments = self.uuid_arguments
         doc = self.db.query('events',
                 {'_id': id_, 'persons.person_id': person_id})
-        ret = {'action': 'delete', 'person_id': person_id}
+        ret = {'action': 'delete', 'person_id': person_id, 'uuid': uuid}
         if doc:
             merged, doc = self.db.update('events',
                     {'_id': id_},
@@ -686,7 +699,7 @@ def run():
     # database backend connector
     db_connector = backend.EventManDB(url=options.mongo_url, dbName=options.db_name)
     init_params = dict(db=db_connector, data_dir=options.data_dir, listen_port=options.port,
-            authentication=options.authentication)
+            authentication=options.authentication, logger=logger)
 
     # If not present, we store a user 'admin' with password 'eventman' into the database.
     if not db_connector.query('users', {'username': 'admin'}):