There is a video embed on the homepage of the "Youth for Western Civilization" of Tom Tancredo attempting to give a speech at UNC-Chappell Hill. The tactics on display by those that disagree with him are repugnant.
I recently attended a speech by David Horowitz at the University of Texas. There were self-described bolsheviks and 'anti-fascists' protesting his mere presence on campus. They also used similar tactics in order to prevent the man from speaking. They claimed it was their first amendment right. The irony was lost on them.
http://www.westernyouth.org/index.htm