Monitored CCTV en masse all but wiped out football hooliganism in the UK. Millwall vs West Ham and Rangers vs Celtic can still be pretty dangerous, but it's pretty much gone. We're the most watched nation in the world. Hooligans are identified on their way to the matches, and most of them have to report to the police station at kick off time when their team plays.
Used to be a big problem here. Not for me tho. Everyone felt sorry for the Wombles cos we had no fans so there wasn't much fighting. Got a bottle round the back of my head on the way out of a game. My mates pointed him out to police and the guy was a fellow Womble who thought I was an opposition fan because me and my mates didn't wear club merch on matchday. Banned from all football matches for life, jailed for 18 months (he had other warrants out of his arrest). I've seen similar incidents broken up quicky by police too.
There's zero tolerance. It works, to be fair.