I watched a documentary on Man U on Netflix titled "Class of 92", and started reading about them on Wikipedia which no doubt led to the hooligans page. We know they are insanely passionate about their clubs, and that they have set places to meet before and/or after to fight. My question is, do they only act like hooligans on game day? Or is it year round? If I'm wearing a Liverpool shirt in Manchester territory on a Tuesday am I going to get my brains beat in? Or only if they are to meet each other that day?

Also, seemingly cities with two teams would tend to have supporters from the two teams working together, correct? Quite perplexing if you ask me.

I think the hooligan situation has calmed a great deal since the mid-90s. With the Liverpool/Juve deaths, the European ban for English teams, and the Taylor Report, public hooliganism really slowed. Of course there are occasional issues but much of what's left of it happens away from public consumption. I think walking down most streets in an opponents shirt would probably be safe.