If the players were doing this in all of our away games, then I'd be more concerned. But to do it in an extremely hostile crowd against your rival is fair game in my opinion. As long as its not flipping off the crowd or anything over the top or vulgar. But doing the upside down U and breaking it over your knee is absolutely hilarious, especially doing it with a smile. You've got to be REALLY sensitive to get too mad about that.
In the meantime their crowd is chanting F U BYU or F THE MORMONS