I dont watch regional Soccer, but I remember last FIFA-World Cup... Spain vs. Germany
we were at a bar and watched it on a projection-screen...
anyway it was a german bar in germany... and when spain shot the 1:0... there were these 2 Guys cheering up with trollface.jpg... and even I had the urge to punch them... cuz they werent fans of spain, they were just against germany... I dont like that kinda attitude...
nonetheless... I imagine if more alcohol is involved I see this thing easily escalating... because Guy 1 is frustrated and Guy B is upbeat... which frustrates Guy 1 even more... and if Guy B is a total dick and Guy 1 over-aggresive... you dont need soccer for this to be an disaster...
and I guess this also applies for regional soccer teams...
well and there is another theory... certain people just love violence... and soccer is the most popular sport... so if you are looking for trouble... you look at popular places... ergo soccer-places...
p.s.: I prefer Tennis - never heard of Federer-Hooligans... and even though there are players I dont like... I rarely see myself judging others for their favourite players... but I tend to hate people who are pickin on my Caroline...