I have went to Houston, NY Jets, Patriots, Dolphins and Packers away games, have never had a big problem. There was a kid at the Dolphins game who was just a complete jerk. I have witness Bills fans throwing snowballs (fastballs) aimed for the heads of patriots fans in OP, I did not like seeing that but it was also funny at the same time. However, when there is good packing snow around and a rival is in town, probably idiots from any fan base would do this. Idiots are the exception not the rule.