       when 'Topic'           then fetchChannelActivities params.slug, cb
       when 'Message'         then SocialChannel.fetchActivities client, { id: params.slug, sessionToken }, cb
       when 'Post'            then SocialMessage.bySlug client, { slug: params.slug }, cb
-      when 'Announcement'    then cb { message: 'announcement not implemented' }
+      when 'Announcement'    then cb new KodingError 'announcement not implemented'
       else fetchGroupActivities cb
 
   reqs = [

  fetchProfileFeed = (client, params, cb) ->
    JAccount.one { 'profile.nickname': entryPoint.slug }, (err, account) ->
      return cb err if err
      return cb { message: 'account not found' } unless account
      SocialChannel.fetchProfileFeed client, { targetId: account.socialApiId }, cb

  fetchActivitiesForNavigatedURL = (params, cb) ->

    # fetch channel first
    SocialChannel.byName client, { name: channelName }, (err, data) ->
      return cb err if err
      return cb new KodingError 'channel is not set'  unless data?.channel

      # then fetch activity with channel id
      SocialChannel.fetchActivities client, { id: data.channel.id, sessionToken }, cb
