Facebook, the world’s largest social network, is no stranger to litigation or criticism for its utilization of user data that has resulted in lawsuits. And one of those in particular complained about what happens when Facebook intercepts messages between users, compiles data, and shares that data with marketers. On Tuesday, November 3, U.S. District Judge Phyllis J. Hamilton ruled that Facebook, Inc., must disclose that market data.

The lawsuit, filed by Facebook users in 2013, accused Facebook of scanning private messages sent between users. The suit alleges that until October 2012, Facebook systematically scanned users’ private messages for URLs to allow targeted advertising. The users tagged Facebook’s practices as violating the Electronic Communications Privacy Act (also referred to as the Wiretap Act) and California’s privacy laws and ethical codes.