Housing rights advocate organizations sued Facebook in Manhattan federal court Tuesday over what they allege is the social media giant’s practice of allowing landlords and real estate brokers to keep certain groups of users from seeing housing ads.

According to the complaint filed in the U.S. District Court for the Southern District of New York, Facebook allows housing advertisers access to a pre-populated list built on the personal information shared by Facebook users. These advertisers are then able to exclude housing seekers from viewing or receiving rental or sales ads based on legally protected categories, such as family status and sex.