I've never played this game with cops! I wouldn't know how many is suitable ;o They do have a pretty revealing role, though so shouldn't be too many of them since they can search members every night and stuff. But yeah, let's discuss role setup while we wait for our last two contestants. 4 mafia sound good to you people?

edit:

Mullet: Dead members will not be allowed to add information to the game after they're dead, or make accusations etc. People not in the game shouldn't post much at all. And yes, the mafia will have to communicate through PM or IM.