I, unfortunately, never got the chance to participate in Mafia, but it did always seem like a fun event. It is unfortunate that some people had to cheat in order to try and get somewhere, but I'm almost positive that we would be able to rework the game in order to prevent any sort of tipping off (aside from blocking PMs - that could be a major problem for urgent means of communication between pirates.)
If it does come to the day where people are needed to help run the Mafia, I would be more than glad to put my talents to use. But, otherwise.... well, let's just say I've seen Goodfellas way too many times to be trusted. Watch yer back, kiddos