BuddyPress.org

@antonrsa Iv’e got the wpmu dev Content Monitor plug-in, have a look at the plug-in at their site ( http://premium.wpmudev.org/project/content-monitor ) and let me know if it could help you, though I would ask that if you modify the plug-in you release it to the respiratory.

It should be a good base to do what you want to do.