Some of those questions have come from members of Congress who question if Google is sacrificing its users to boost its online advertising business as it pushes into new areas such as social networking and mobile devices.
Reps. Ed Markey (D-Mass.) and Joe Barton (R-Texas) on Friday asked the U.S. Federal Trade Commission to probe whether the changes violate Google's settlement last year over its now defunct Google Buzz social network. People have different options to evade this kind of tracking. They can open Google accounts not associated with their real names. Or they can just not log in.
-- Jessica Guynn
Photo: A sign for Google is displayed behind the Google android robot, at the National Retail Federation, in New York on Jan. 17, 2012. Credit: Mark Lennihan/AP Photo