"Zynga reportedly makes around one third of its revenues from cost-per-action advertising, which is estimated to amount to between USD 33-84 million per year for the company, and the lawsuit claims that Facebook shares "a substantial portion" of this revenue. FishVille, Zynga's most recent Facebook title, was recently briefly removed from the site for featuring cost-per-action advertising. The ads allegedly trick users into signing up for unauthorised phone charges or expensive mail order products. They are called 'free trials' but one plaintiff claims she faced a USD 165 charge on her phone bill for 'free' items delivered to her that she is unable to return or obtain a refund for. " - Graham Sergeant