Rhiannon...I don't know how old you are but I lived through the Mods and Rockers era and their violence (which palls into insignificance compared to the real sadistic violence metered out today) was between themselves and was a form of gang warfare, something which is part of our history. It didn't involve the public and was easily contained. They didn't loot shops, toss petrol bombs or carry guns as a matter of course and it wasn't politically orchestrated.