Moving away from the topic of my previous posts, I'd like to bring up a possible solution when someone uses the defense "It's what my character would do!" for something that creates needless conflict within the party or player group.
When they say "But I was acting in-character!" Reply with:
"He dies. Roll up a character who doesn't act like that."
@Skaven:
I know. These guys are awful. Some of them can do it in a way that's still fun, because they apologize out of character, and only do it when they can easily justify it in character to the other players' satisfaction.
Still, it's pretty annoying most of the time. Luckily, most of them play rogues, so no one was trusting them anyway.