Threat Level reports on the Facebook privacy class action spawned by its Beacon feature from a while back (the complaint is linked in the Threat Level post). 

This lawsuit raises a slew of interesting issues - a ton of fodder for the tech law geek.  All of the statutes involved are technical.  Harm is somewhat speculative (in some cases there may be statutory damages).  The terms of service issue complicates the issues somewhat.  The defendants will undoubtedly skirmish on the side around indemnification/fault.
 
Plaintiffs are represented by counsel who have gained their class action chops in these types of (internet/consumer) lawsuits.  It will be interesting to see what happens.  (The case is initially assigned to Magistrate Judge Seeborg, but either of the parties could cause re-assignment by declining to proceed in front of a magistrate judge.)