When I went to middle school near Youngstown, we had pretty much half Steelers fans half Browns fans. It used to be pretty crazy during game weeks. It did suck though when the Browns moved, everyone was kinda sad.
I don't think I would ever wish bodily harm on any other teams fans though. "Pouring" ice (how do you pour ice, it's already frozen, unless it was cubes) on the floor in front of someone to make them fall is kind of a dick move.