It depends. When Canada's anti-spam law was introduced in 2014, the intent was to allow a private right of action effective July 1, 2017. This would theoretically mean US/foreign companies could be dragged into class-action lawsuits in Canada. This private right of action was delayed and is currently under review, but nevertheless anyone marketing to Canadians is subject to CASL laws, regardless of where their business is located. We'll see what happens, but if/when the private right of action is implemented it could potentially be a big deal.

IANAL but I can imagine a similar situation happening with GDPR.