Facebook is changing its rule that let advertisers use the name, and photo, of any user that "Liked" its product (it is often necessary to click "Like" to leave a comment on a story or page about a product - even though that comment might be neutral, or even a complaint) - the so-called Sponsored Story service.

To settle a class action lawsuit brought in California, Facebook has agreed to give people an "opt-out" choice from becoming unpaid endorsers.

A lawyer for the plaintiffs estimated that giving users such a choice would cost the social network $103 million in lost revenue, according to a New York Times report.