If you're interested in how insanely stupid people's behaviour can be, then I can think of no finer example than this, which Nick just emailed me. It's about Team Fortress 2, an online FPS (think Doom/Quake):
Valve added unlockable weapons, based on achievements. People used software to unlock the achievments, Valve got their rage on and were all "seriously, just play the game" and took these people's items away. Fair enough.
Valve add hats into the game. These hats are totally cosmetic and do NOTHING in-game apart from look neat; They are dropped very randomly (every few hours, you have a less than 1% chance of getting one) so are quite rare
People WANT hats.
So some one sets things up so you can stay logged in and just idle without getting kicked in order to acquire said hats.
Valve decide the other day that this isn't a good thing, so remove the hats people have gained through idling, give a free hat (actually a halo, in fact) to everyone who -hasn't- used this idling method and announces that going forward, they'll remove ALL the items from people who use the idler to get hats. That's all - they don't ban anyone, they don't take away the hats people got on normal servers.
Cue insane internet rage and factionalism as some servers ban people with halos, some ban people without and the steam forums erupt into outright war
All this over completely free items that have no in-game effect.