Animals!

it turned into a street fighter in the end :D
anyway , i dun know why people don't understand that football is a sport of peace and respect !! these stupid fans ruin the game :S

^OVERREACTION MUCH? It's just a bit of skirmishes. Nothing more than what happens at MAJORITY of rivalries in Europe.
I'll tell you one thing though, the police love a good fight... well, at least they do in the states. My friend is a copper and he says when a brawl breaks out, they can't wait to jump in! Then again, that's mostly to do with the fact that they have batons & Steel clubs

^ Also do to the fact that America, their police, and its whole system is corrupted.

Pretty tame, really.

@tdot: I think they just like the adrenaline rush it brings, many of them are ex-military. But, I agree that many police officers are absolute dicks here though. I've had my issues with them in the past. Depends on your luck I guess.
Also, unlike Europe, they have guns here so if shit really kicked off... they'd be more confident that they'd be able to protect themselves.