Facebook is being sued over claims it intercepts users' messages and sells information to marketers and advertisers.  

The two Facebook users who brought the suit say when users compose messages with links to another website, the social network scans the content of the message and follows the link to find information on the sender's web activity.  

Facebook, the plaintiffs claim, then sells that information to advertisers and marketers.  

The plaintiffs want their case, which was filed in San Jose, California's federal court, to be declared a class-action suit.