Tracking users after they log out and violating US wiretapping laws – these are the allegations behind a 15-billion-dollar nationwide class-action lawsuit filed against Facebook in California.

­The suit, combining 21 cases of alleged privacy violations by the social networking giant, was filed on Friday in the Federal Court in San Jose, Emil Protalinski writes on ZDNet.com. In their consolidated complaint, the plaintiffs claim that Facebook used cookies to track them across the Internet.

And yet, where does the staggering sum of the lawsuit come from? Violation of the Federal Wiretap Act provides suggests compensation of US $100 per day per user for every case of violation, up to a maximum of US $10,000 per user.