Well, they probably realize that it is the second foul that gets called...meaning anyone practicing vigilantism would be caught, arrested, tried and convicted.
I have a simpler question: why do universities get away with hiring scum bags like Ayers and Angela Davis to preach their anti-American hate speech to our children.
That's what I want to know also. I recently watched a YouTube video (Since pulled I believe)of a white male professor and a black women (not sure of her qualifications but it was a debate. The black women said something that set the white male professor off and they went to screaming at each other using foul language and facing off, people kept them separated. The male professor even pulled his pants down and mooned her. I swear if they would have had guns they would have killed each other.