A new Snowden leak reported on the CBC reveals that secretive Canadian spy-agency CSEC was illegally spying on Canadians by collecting information from the free Wifi service in major airports and cross-referencing it with intercepted information from Wifi at cafes, libraries and other public places in Canada.

The agency is prohibited from spying on Canadians without a warrant, but it captured data on all travellers in a Canadian airport, ensuring that it captured an enormous amount of sensitive information about Canadians. It claims that because it did not "target" Canadians (that is, it spied on everyone, regardless of nationality), they somehow weren't "spying" on Canadians.

The CBC article features a brilliant and incandescent Ron Diebert (who runs the Citizenlab centre at the University of Toronto and wrote one of the best books on Internet surveillance, Black Code), and an equally outraged Ann Cavoukian, the Ontario privacy commissioner, who is one of the most savvy privacy advocates in any government.

Indeed, the spy agency boasts in its leaked document that, in an apparently separate pilot project, it obtained access to two communications systems with more than 300,000 users, and was then able to "sweep" an entire mid-sized Canadian city to pinpoint a specific imaginary target in a fictional kidnapping. The document dated May 2012 is a 27-page power-point presentation by CSEC describing its airport tracking operation. While the document was in the trove of secret NSA files retrieved by Snowden, it bears CSEC's logo and clearly originated with the Canadian spy service.

CSEC used airport Wi-Fi to track Canadian travellers: Edward Snowden documents [Greg Weston, Glenn Greenwald and Ryan Gallagher/CBC News]