I think there's a lot of confusion about this. I've never personally worked any security jobs, but I had plenty of friends who did - including on my college campus. I think I have a pretty good understanding of what happened. I'll list the things that are clear from the video.
1. The kid was being long-winded and aggressive in his question.
2. He was offending many of the other students, as you can tell by how many of them get up to leave while he prefaces his question.
3. Security acts on this to remove him from the hall. This was purely at their discretion.
4. He throws a fit.
5. Security subdues him.
6. He continues to fight.
7. Security tazers him.
I split up these events based on their relevance. These are two separate instances, they just happen to follow one another. Initially, based on the way that security was dealing with him, it appears as though he was just to be escorted out. The handcuffs and tazer never came out until he fought back. Just because he is screaming that he's being arrested doesn't mean he is. It's pretty clear that the guy just wanted to get a rise out of the audience, and that he had a political axe to grind. He is not getting arrested until he is resisting the security personnel trying to remove him from the room.
Boomer and others: I think if you break it down and look at it this way, I don't think you can really hold the security officers at fault. The guy was being rude.
he threw a fit because he knew they didn't have a right to do that. If you ask me, they should've let Kerry answer the questions.