From here:

A private member’s bill set for debate Thursday in Ottawa would make it a crime to cover your face with a mask or other means during a riot.

[….]

The Alberta MP’s bill exempts people from the bill that have a “lawful excuse” for covering their face. It does not define what a lawful excuse would be under the proposed legislation.

It’s anyone’s guess what would constitute a “lawful excuse”, but I’m betting that if the bill passes, the next riot will see a dramatic increase in burkas.