Well, the truth is, the UK have a much bigger problem with sectarianism and bigotry in sports than we do. I know it was a big debate in Scotland about new legislation that would make any "offensive behavior" punishable by law. My feeling on this subject is that the clubs should self-regulate and weed out the problem on their own. Ban fans from the games, kick them out of its seen and the club feels its offensive, etc.
I'm okay with stopping this behavior, but I'm not okay with the police doing it.