CSEC used airport Wi-Fi to track Canadian travelers: Edward Snowden documents

A top secret document retrieved by US whistleblower Edward Snowden shows that Canada's electronic spy agency used information from the free Internet service at a major Canadian airport to track the wireless devices of thousands of ordinary airline passengers for days after they left the terminal.

Ronald Deibert, one of Canada's foremost authorities on cyber-security, says the clandestine operation by the Communications Security Establishment Canada (CSEC) was almost certainly illegal. The spy agency is supposed to be collecting primarily foreign intelligence by intercepting overseas phone and internet traffic, and is prohibited by law from targeting Canadians or anyone in Canada without a judicial warrant.