The Bilodeau sieve is an identity/identify concept, created by Robert J. Sawyer.
From Wonder, the 3rd instalment of the WWW-trilogy by Robert J. Sawyer:
The Bilodeau sieve, developed by Marie Bilodeau of the RCMP, was based on a simple premise: the specific websites and blogs regularly accessed by a person are idiosyncratic to that person.
Tony’s own morning ritual included visiting Slate and the Huffington Post — hardly an unusual combination — but also TrekMovie.com (the new film was shaping up to be so good!), MobileRead.com (he had a fascination with ebook-reading hardware even though he preferred paper books), Wired’s Threat Level blog, and the US weather forecast for Miami (which was where his parents had retired to), plus checking Twitter for the hashtags #nsa and #aquarium. Those eight things were enough to identify him even if he didn’t log on or post anything of his own.