diff --git a/config/alfresco/activities/activities-feed-context.xml b/config/alfresco/activities/activities-feed-context.xml
index 59084cc311..e6d0a14511 100644
--- a/config/alfresco/activities/activities-feed-context.xml
+++ b/config/alfresco/activities/activities-feed-context.xml
@@ -25,6 +25,7 @@
    <!-- cleans out-of-date feed entries -->
    <bean id="feedCleaner" class="org.alfresco.repo.activities.feed.cleanup.FeedCleaner">
       <property name="feedDAO" ref="feedDAO"/>
+      <property name="siteService" ref="SiteService"/>
       <property name="maxAgeMins">
          <value>${activities.feed.max.age.mins}</value> <!-- max age in mins, eg. 44640 mins = 31 days -->
       </property>
diff --git a/source/java/org/alfresco/repo/activities/feed/cleanup/FeedCleaner.java b/source/java/org/alfresco/repo/activities/feed/cleanup/FeedCleaner.java
index a7efe3b4ea..2d96bcb4ed 100644
--- a/source/java/org/alfresco/repo/activities/feed/cleanup/FeedCleaner.java
+++ b/source/java/org/alfresco/repo/activities/feed/cleanup/FeedCleaner.java
@@ -24,6 +24,8 @@ import java.util.List;
 
 import org.alfresco.repo.domain.activities.ActivityFeedDAO;
 import org.alfresco.repo.domain.activities.ActivityFeedEntity;
+import org.alfresco.repo.security.authentication.AuthenticationUtil;
+import org.alfresco.service.cmr.site.SiteService;
 import org.alfresco.util.PropertyCheck;
 import org.alfresco.util.VmShutdownListener;
 import org.apache.commons.logging.Log;
@@ -45,11 +47,18 @@ public class FeedCleaner
     
     private ActivityFeedDAO feedDAO;
     
+    private SiteService siteService;
+    
     public void setFeedDAO(ActivityFeedDAO feedDAO)
     {
         this.feedDAO = feedDAO;
     }
     
+    public void setSiteService(SiteService siteService)
+    {
+        this.siteService = siteService;
+    }
+    
     public void setMaxAgeMins(int mins)
     {
         this.maxAgeMins = mins;
@@ -122,11 +131,13 @@ public class FeedCleaner
                 for (ActivityFeedEntity feed : feeds)
                 {
                     String siteId = feed.getSiteNetwork();
-                    String feedUserId = feed.getFeedUserId();
+                    final String feedUserId = feed.getFeedUserId();
                     String format = feed.getActivitySummaryFormat();
                     
                     List<ActivityFeedEntity> feedToClean;
                     
+                    int feedUserSiteCount = 0;
+                    
                     if ((feedUserId == null) || (feedUserId.length() == 0))
                     {
                         feedToClean = feedDAO.selectSiteFeedEntries(siteId, format);
@@ -134,9 +145,22 @@ public class FeedCleaner
                     else
                     {
                         feedToClean = feedDAO.selectUserFeedEntries(feedUserId, format, null, false, false);
+                        
+                        if (siteService != null)
+                        {
+                            // note: allow for fact that Share Activities dashlet currently uses userfeed within site context
+                            feedUserSiteCount = AuthenticationUtil.runAs(new AuthenticationUtil.RunAsWork<Integer>()
+                            {
+                                public Integer doWork() throws Exception
+                                {
+                                    return siteService.listSites(feedUserId).size();
+                                }
+                            }, AuthenticationUtil.SYSTEM_USER_NAME);
+                        }
                     }
                     
-                    if (feedToClean.size() > maxFeedSize)
+                    if (((feedUserSiteCount == 0) && (feedToClean.size() > maxFeedSize)) ||
+                        ((feedToClean.size() > (maxFeedSize * feedUserSiteCount))))
                     {
                         Date oldestFeedEntry = feedToClean.get(maxFeedSize-1).getPostDate();
                         
diff --git a/source/java/org/alfresco/repo/site/SiteServiceImpl.java b/source/java/org/alfresco/repo/site/SiteServiceImpl.java
index 28ac8355bb..84191579cb 100644
--- a/source/java/org/alfresco/repo/site/SiteServiceImpl.java
+++ b/source/java/org/alfresco/repo/site/SiteServiceImpl.java
@@ -680,8 +680,29 @@ public class SiteServiceImpl implements SiteService, SiteModel
     /**
      * @see org.alfresco.service.cmr.site.SiteService#listSites(java.lang.String)
      */
-    public List<SiteInfo> listSites(String userName)
-    {        
+    public List<SiteInfo> listSites(final String userName)
+    {
+        // MT share - for activity service system callback
+        if (tenantService.isEnabled() && (AuthenticationUtil.SYSTEM_USER_NAME.equals(AuthenticationUtil.getRunAsUser())) && tenantService.isTenantUser(userName))
+        {
+            final String tenantDomain = tenantService.getUserDomain(userName);
+            
+            return AuthenticationUtil.runAs(new AuthenticationUtil.RunAsWork<List<SiteInfo>>()
+            {
+                public List<SiteInfo> doWork() throws Exception
+                {
+                    return listSitesImpl(userName);
+                }
+            }, tenantService.getDomainUser(AuthenticationUtil.getSystemUserName(), tenantDomain));
+        }
+        else
+        {
+            return listSitesImpl(userName);
+        }
+    }
+    
+    private List<SiteInfo> listSitesImpl(String userName)
+    {
         List<SiteInfo> result = null;
         
         // get the Groups this user is contained within (at any level)