http://www.schneier.com/blog/archives/2009/11/virtual_mafia_i.html
This story is a bit old, but Schneier reminded me about it today.
Basically, in one online game (The Sims Online, I think?) they allow players to penalize each other, and players with a low reputation get penalties or something. So a group of people got together and started racketeering -- basically, if you don't pay them protection or give them what they want, a whole bunch of them will penalize you, lowering your rep so far that the game becomes unplayable.
It's actually a really funny situation -- an accident side effect of a feature that probably seemed good at the time.
Awesome. I join play The Sims Online and start an IRA. Any Irish user will be welcome, and any British user will have their house pipe-bombed. Anyone else can pay us money, and when someone tries to extort any of us, we kill their character.
What's even more fun, is when these sort of things are allowed. You then get mafias fighting each other over harassing new players. Very interesting to watch.
www.there.com
My avatar is Camel