Went to a Serie D match two weeks ago in Ercolano (Herculaneum to the Romans) against Casertana. I was quite shocked by the level of fan violence at and after the game - and believe me I've seen plenty of hooliganism over the years. There couldn't have been more than about 1000 people at the game, but I would estimate that about 3/4's of the crowd seemed intent on fighting. Is this typical, or typical of the Naples area, or was I just unlucky? The trouble was clearly expected as there were loads of riot police present well before the game started.
We were just talking about derbies on Italy threads: I suppose Ercolano-Casertana was a derby too! Well we can't say that every game has a 3/4 of crowd ready to riots, but we should admit hooliganism is still a big problem for Italy. Fans riots happen often, much more often during derby or between supporters groups with hard rivalry. Usually these fans riots doesn't involve hundreds of fans, only little groups trying to catch the others near the train/bus stations or directly into the areas around stadia. This happens mainly in the southern Italy (but not only there): it happens in lower championships too, where police checks are less strict and fans could get in touch easier. Something similar happened in England, when Premier League renforced security checks and hooligans had to go to lower divisions to find less police and express themselves better ...