Canada’s controversial Concealment of Identity Act banning the wearing of masks during riots and "unlawful assemblies" has just gone into law, carrying with it a 10-year maximum sentence, reports CBC News. The private member’s bill was introduced in 2011 by MP Blake Richards in response to the increasing prevalence of vandalism at political protests and sporting events.

What distinguishes an unlawful assembly from a lawful one?

It’s noteworthy that there is already a federal law in Canada that prohibits wearing a disguise "with intent to commit an indictable offence" and carries the same 10-year maximum. The distinction in language is deliberate: Richards has criticized the existing law for its high burden of proof. Now, instead of requiring intent to commit a criminal act in order to charge a protester, he or she only needs to be in attendance at an unlawful assembly. Richards has insisted that the law is necessary for dealing with protesters "pre-emptively," before a protest escalates. And what distinguishes an unlawful assembly from a lawful one? The CBC points out that it’s "an assembly of three or more persons who, with intent to carry out any common purpose, assemble in such a manner… as to cause persons in the neighbourhood… to fear… that they will disturb the peace tumultuously."

Many, such as Osgoode Hall Law School Professor James Stribopoulos, have pointed to the possible "chilling effects" posed by making it unlawful to disguise one’s identity at a protest, say to prevent against reprisals from your boss or coworkers, or to avoid facial recognition software. The CBC notes that exceptions can be made for "lawful excuses" for face covergings, like religion or medical conditions, but Stribopoulos has countered that most judgments about an excuse’s "lawfulness" will fall to police in the field.