Lol.
It’s the paradox of freedom. With free elections, you can get all kinds of candidates running for office. That can include candidates who want to abolish free elections. 
What do you do? Ban those candidates? No. Because then you wouldn’t have free elections.
Instead you maintain enough societal sophistication that the percentage of people who are willing to vote for the outright fascists stays small. It’s messy, but it’s worth it. Because freedom.
Harassment is a crime in Canada. Did they commit harassment? If so, he can have them arrested. (It’s probably also against the student code of conduct or whatever.)
If they did something ridiculous and annoying without breaking any rules, too bad, so sad.
If anything ridiculous and annoying can be banned, everything ridiculous and annoying can be banned. Including Monty Python.