I wuz gonna stay out of this one. But since Ken jumped in, I have to share my two cents.
Of all the opinions expressed so far, I'm mostly onside with Colby Cosh.
When Coulter comes to town, it says more about those wanting to hear her than who it is doing the speaking. Denying her her pulpit does not sway the choir she would be preaching to.
However as Dawg points out, this is not a clear-cut use of violence to shutdown a public event. What the shrieking right ignores, is that as much as people have the right to hear Coulter, people still have the right to protest her. Free speech cuts both ways (and this where Cosh and I part ways a bit). And oftentimes when the divisions are deep, that clash is very strong.
Using that clash to claim censorship is a dishonest portrayal of this disagreement. But given what Coulter is all about, that's not really a surprise now is it?