A top secret document leaked by US whistleblower Edward Snowden and obtained by CBC News shows that “Canada’s electronic spy agency, the Communications Security Establishment Canada (CSEC), 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.”

After reviewing the document, Citizen Lab Director Ron Deibert said the clandestine operation by the CSEC was almost certainly illegal.

“I can’t see any circumstance in which this would not be unlawful, under current Canadian law, under our Charter, under CSEC’s mandates,” Deibert told the CBC.

Read the full coverage on the CBC.

Read Deibert’s editorial in the Globe and Mail.

See more media coverage in CBC The National (video), CBC Metro Morning, Huffington Post (French), Rabble, Vice and ArsTechnica.

UPDATE: On 14 February, Deibert commented on the recent federal watchdog ruling absolving Canada’s electronic spy agency of using data from a Canadian airport internet service to track passengers.