It's not an isolated incident.
"Last year, Canada banned the vehemently anti-war, left-wing British MP George Galloway from entering their country, on extremely dubious "national security" grounds," blogged Glenn Greenwald, in a detailed post about the provost's letter to Ann Coulter. The blogger continues, "Galloway is a vociferous critic of Canada's involvement in the war in Afghanistan as well a defender of Hamas, which were clearly the bases for his exclusion."
Francois Houle, Vice-President Academic and Provost at the University of Ottawa, was the author of the letter to Ann Coulter. On the Provost section of the university's website, there is a page called Dialog and Controversy which describes the kind of speech Her Provost is inclined to ban:
Sometimes members of our internal or external communities pressure the University to ban a specific activity that presents an objectionable position. However, if the ideas presented are not illegal, the University will not intervene unless there is evidence that the safety of participants, including the speaker, organizers and audience, may be at risk...How can "an idea" be illegal -- at a university no less? Since when was "safety" supposed to dictate what can and cannot be said? In the capital of Canada, evidently neither the free exchange of ideas nor courage is an academic value.