The sentiment expressed in a famous New Yorker cartoon – “On the Internet, nobody knows you’re a dog” – seems as dated today as Goth fashion (the cartoon was published in 1993, after all). Web companies and law enforcement agencies alike are using new technologies and data-mining tools to pierce Internet users’ anonymity and track their online activities. But one place the sentiment still rings true is Canada, where, in R. v. Spencer, the Supreme Court recognized a constitutional right to use the Internet anonymously. This new right was the basis for the court’s ruling that police must get a warrant in order to require an Internet Service Provider to disclose the identity of a person associated with a certain Internet Protocol address. This sort of information can be obtained in the United States with only a subpoena. So if your dog starts heading north this summer, now you know why.