They are few and far between, but go and see a Twenty20 match and you will likely see some rowdy types drinking too much and singing bawdy tunes badly. Honestly, the best way to deal with that is to frown at them, this is a cricket match not some ribald hostelry.
Actual crowd violence is pretty rare in cricket. Apparently a world cup match in India was called off because of it back in 1996 though. They get pretty passionate about their cricket over there.
bastard by name