Online gaming in general for that matter. I've pretty much given up on it unless I already know the people I'll be playing with.
I still enjoy it from time to time, but some people do the weirdest stuff. I was playing a Half-life 2 mod the other day (Dystopia), and I watched a kid hack at a wall with a sword for like 10 minutes. I was in 'spectator mode'...and he wasn't stuck or anything, because he kept moving around from time to time, but he'd always go back and hack at the wall, in the same spot. It's like, maybe mental patients are getting online access for gaming lately, or something?
Sometimes it just as fun watching these idiots as it is playing the game.
mrC