WSJ: “Google’s iPhone Tracking”
Still polishing my technical analysis of how Google, Vibrant, MIG, and PointRoll circumvented Safari cookie blocking. Stay tuned.
— Jonathan Mayer (@jonathanmayer) Februar 17, 2012
Google Inc. and other advertising companies have been bypassing the privacy settings of millions of people using Apple Inc.’s Web browser on their iPhones and computers […]
To get around Safari’s default blocking, Google exploited a loophole in the browser’s privacy settings. While Safari does block most tracking, it makes an exception for websites with which a person interacts in some way—for instance, by filling out a form. So Google added coding to some of its ads that made Safari think that a person was submitting an invisible form to Google. Safari would then let Google install a cookie on the phone or computer. […]
The Google code was spotted by Stanford researcher Jonathan Mayer and independently confirmed by a technical adviser to the Journal, Ashkan Soltani, who found that ads on 22 of the top 100 websites installed the Google tracking code on a test computer, and ads on 23 sites installed it on an iPhone browser.