Some of the posts on here are just unreal ! I don't condone any form of violence but get real here - a bunch of knuckle draggers come steaming into your face, threatening to beat the crap out of you, throwing stuff, spitting on you and more and you are supposed to do what ? Stand there and say "hey, I don't condone violence so I'll just ignore you ?".
It was heat of the moment big time, people were angry, people were scared and in those circumstances any human being will respond otherwise there is something not quite right about them.
The failing inside the ground was WMP+Nose Stewards+SHA and what Villa did in response should not be over-analysed as they found themselves in a real shite situation so unless you were there and facing those scumbags then you shouldn't judge.