I dare say vomiting on someone is a hell of alot different than say; stabbing someone [http://latimesblogs.latimes.com/lanow/2009/04/man-stabbed-after-dodger-stadium-home-opener.html] or beating the hell out of a fan from an opposing team.
It goes on at almost every venue, I don’t believe any team or sport is exempt.
I can tell you stories about incidents at New York Jets games that are unbelievable. I was interested in them as a Giants fan because the New Jersey Sports & Exposition Authority -- the owner of Giants Stadium in the Meadowlands where both teams play -- would impose restrictions on fans of both teams in response to the nonsense that was pretty commonplace at Jets games back in the 1980s.
One particularly troubling game was a Monday night game back in the late 1980s when the Buffalo Bills were one of the worst teams in the NFL but somehow managed to win a late-season game to knock the Jets out of the playoffs. People watching the nationally televised game were treated to the spectacle of seeing fans in the stands lighting garbage, clothing and souveniers on fire during the fourth quarter. The NFL actually threatened to impose a long-term ban on Monday night home games for the Jets over that one.
Without question, the most civilized fans I've ever met were in Minnesota. It must be something in the water, or maybe it's that culture of civility that the Upper Midwest is known for (I've heard the same thing about Green Bay fans). The Metrodome was one of the first major sports venues in the U.S. to enact a smoking ban (about 20 years ago). At first they were hesitant to do this because they feared even a small bit of controversy, but it turned out that the smoking ban was pretty pointless because nobody was smoking at Vikings or Twins games anyway. LOL.