After exposing scandalous spy programs of American and British intelligence services, Edward Snowden leaked some info on the Canadian Communications Security Establishment (CSEC).
According to top secret documents, leaked by former NSA contractor, CSEC agents used public Wi-Fi in one of the biggest airports of Canada to track wireless devices of thousands of passengers for days when they left the terminal. Data, collected by the surveillance program, included hotel, cafes, restaurants and other public places visited by passengers, as well as means of transportation.
Canadian authorities said that CSEC’s operation was almost certainly illegal. Any investigation activities aimed to intercept phone and internet communications of Canadians or anyone in Canada are impossible without a judicial warrant.
CSEC chief John Forster commented that no Canadian communications were (or are) targeted, collected or used. "Protecting the privacy of Canadians is our most important principle” - he said.
Indeed the documents leaked by Snowden indicate the technical possibility of such an operation but provide no evidence of continuous surveillance. It is also clear that information collected over 2 weeks had no personal data.
However, this raises some question about the CSEC's purpose developing this tracking system and how the secret files ended up in NSA’s archive. Perhaps the NSA helped their colleagues from Canada to implement or test the system.