The Supreme Court of Canada says police need a search warrant to get information from Internet service providers about their subscribers' identities when they are under investigation.
The high court's landmark 8-0 ruling on online privacy issues comes in the appeal of a Saskatchewan man facing child pornography charges.
The case has implications for the federal government's current cyber-bullying bill, setting the stage for another political clash between the Harper government and the Supreme Court.
The ruling deals with a 19-year-old Saskatchewan man who was charged with possessing and distributing child pornography after police used his Internet address to get further details from his online service provider, all without first obtaining a search warrant.
Lawyers for the man contend that violated his right to be protected from unlawful search and seizure.
But in this specific case, the court ruled that the evidence gathered should not be excluded as evidence from the man's trial, saying the police acted in good faith.