Freedom of Speech threatened at the University of Ottawa?

Read Stephen Chase's article in the Globe and Mail, 23 March, 2010.

Chase writes about the failed attempt of American conservative pundit Ann Coulter to address a crowd at the University of Ottawa the evening of March 23rd. Protesters effectively shut down the venue, creating a situation which was considered 'unsafe' for the talk to continue.

Ezra Levant, a conservative activist, summarized the significance of the evening accordingly: "Isn't it ironic that it takes a provocative American coming to Canada to reveal the shortcomings in Canadian free speech?"

Thus: Should Ann Coulter have been allowed to address the audience at the University of Ottawa? Does the cancellation signify a dangerous threat to free speech in Canada as Mr. Levant argues?