No big surprise here, but the Federal Court decision of HomeAway.com, Inc. v. Hrdlicka stated that:
 I find, therefore, that a trade-mark which appears on a computer screen website in Canada, regardless where the information may have originated from or be stored, constitutes for Trade-Marks Act purposes, use and advertising in Canada.
One of the issues was whether the appearance of the trade-mark on a website viewable in Canada that originated from the United States was "use" of that trade-mark in Canada. The site was for people wanting to rent homes, cottages or apartments for vacations, including some listed in Canada.
This makes perfect sense in the context of the facts where the website had Canadian listings. But consider whether that statement is too broad in general. For example, one would hope that if the facts were that the website was not aimed at or used by Canadians, the mere fact that a mark is on a website that can be seen from Canada should not constitute use in Canada.