Canada's digital surveillance agency has successfully tracked down people who used popular file-sharing services to access material associated with violent jihadi extremists, according to a document obtained from former U.S. intelligence contractor Edward Snowden.

A document outlining a project, dubbed "Levitation," by the Communications Security Establishment was reported Wednesday by The Intercept and CBC News. The document outlines the results of a 2012 operation that targeted downloaders of materials such as bomb-making guides.

Starting with vast amounts of metadata – general information about an Internet communication – from millions of users of popular file-sharing services, the authors of the project sought ways to filter out the overwhelming majority of innocuous material, citing as an example downloaders of the TV show Glee. Focusing on "documents of interest," the program sought to gather metadata about people downloading material associated with radical groups.

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The document provided by Edward Snowden, which is marked "Top Secret" and bears the badge of CSE – formerly CSEC, before a name change at the surveillance agency last year – says the project found 350 "interesting download events" per month. The document does not indicate whether or not the Levitation project or others like it are still operating, although previously leaked materials suggest Levitation is now a routine part of CSE's toolkit.

The Levitation project also sought to track down more information about people who accessed "interesting" material. The document describes one example in which the downloading of "The Explosives Course" from a location in Kenya was traced back to a Facebook user in Dubai.

The document emphasizes that the Levitation experiment also aimed to automate as much as possible the tracking of such events and the identification of Internet users accessing these materials.

According to the leaked document, the researchers made two discoveries as a result of their tracking exercises: a video of a German citizen being held hostage by extremists, as well as a "hostage strategy" for al-Qaeda in the Islamic Maghreb, the Islamist radical group that abducted Canadian diplomats Robert Fowler and Louis Guay in 2008.