Stanford researcher Hristo Bojinov found, that each accelerometer gives teeny tiny deviations from the standard measurements, which are unique to each phone, as no handset gets off the conveyor belt exactly the same as the previous one. They aren't strong enough to affect the way your browser page turns from portrait to landscape, but their exact value can be measured and logged in an online database, leaving a unique "fingerprint" that can identify and track your handset afterwards...Source: http://www.phonearena.com/news/Researchers-find-a-way-to-track-you-via-the-motion-sensors-test-your-phone-here_id48295
