Cool. It's interesting reading through the current thread, and thinking about possible motives for each player. For instance, if a player says that he suspects someone of being a Dopp rather than just being scum, he may have accidentally outed himself as an Agent, and someone who is overly certain of someone's guilt may have accidentally outed themselves as psychic (either of these things being equivalent to painting a big sign on your house saying "Night kill me!").
Actually, it's quite interesting considering what to try and do if plonked down as any particular character, and what strategy you would take. Also I've been trying to consider whether it would be a good idea to say that you have any role other than townie. It would obviously be stupid to out yourself as scum or a high ranking townie, but how about something like War Vet? This could be interpreted as trying to prevent a vigilante attack, however, and result in a lynching nonetheless.
Of course, a medium would be nearly useless to his team unless he outed himself. However, this would make him a target for both mafias and possibly the exterminator, if he doesn't have any better leads. Another problem is that a dead member of the scum team could read what is being told to the medium (if I've read the rules correctly) and pass this information to their own medium, if they also happen to have one.
I suppose the atmosphere in the private mafia chatrooms are a bit different from the thread, since they all know they are with people they can trust (well, except in the Doppelganger camp, who will be painfully aware that there's a 50% chance of them housing an alien operative).
Actually, I have one more question, one that could be potentially quite important for the person who is exterminator:
Controlled Doppelganger
Victory: All non-Exterminator aligned players are dead or Doppelgangers if the Exterminator is dead.
Does that mean that the doppelganger needs to kill all the other Doppelgangers in the group if the exterminator dies, or does it mean that the controlled doppelganger has his goal changed to "Doppelganger win" when the exterminator dies? The second seems problematic, as he could simply direct the night kill at the exterminator and become a normal doppelganger.