This came up on a different thread and I'd much rather discuss it than beat on that dead horse any more, so... 
Do you think there is a correlation between online and offline behavior? Are jerks online necessarily the same in real life, or at least are they considerably more likely to be the same there? What about the opposite, if someone is a great person online does it suggest they are probably the same in person?
My anecdotal submission to this thread is one of my old roommates from the university days. He's happily married, he's a solid professional, I would (and have) trusted him with money and never had a single issue... he's built an extensive real life social network of board games that's ran regularly and fairly, he owns Facebook groups where amateurs trade and buy/sell games where he's gone well out of his way to make sure no one gets scammed... basically I don't have any bad marks against the guy, and I've known him for a very, very long time.
Online he's an asshole! He trolled the shit out of another guild on WoW trying to incite a PvP war with them for the lols, and on one notable episode on Arctic MUSH back in the day he and another guy lured someone to a basement promising him rare loot, closed and locked the door, and PKed him. He trolls with wild abandon every chance he gets because to him online just... isn't real, it doesn't have real consequences I guess? He just separates it completely, and treats what happens there as he wants for his own amusement.
I have other friends who aren't as good examples of this, but that's the one I wanted to bring up since it's relevant. On the other hand I won't pretend there are people I've 'met' only online who just... let's say I wouldn't make a bet aren't assholes iRL as well. I certainly wouldn't risk them having any ability to damage my life, even if they barely know me, just because they can.
What do you think?