The housing-discrimination complaint, filed under the Fair Housing Act, said that advertisers can use Facebook’s ad platform to create target ads that unlawfully favor certain people by suggesting options based on gender or race.

“Facebook unlawfully discriminates by enabling advertisers to restrict which Facebook users receive housing-related ads based on race, color, religion, sex, familial status, national origin, and disability. Facebook mines extensive user data and classifies its users based on protected characteristics,” the complaint said.

“Facebook’s ad-targeting tools then invite advertisers to express unlawful preferences by suggesting discriminatory options, and Facebook effectuates the delivery of housing-related ads to certain users and not others based on those users’ actual or imputed protected traits,” it said.

For example, advertisers can choose to show ads only to one gender, filter out disabled users who show an interest in “assistance dog” or “deaf culture,” and discriminate by national origin by not advertising to people interested in, say, “Latin America” or “Somalia.”

In a statement, Facebook said: “There is no place for discrimination on Facebook; it’s strictly prohibited in our policies. Over the past year we’ve strengthened our systems to further protect against misuse. We’ll continue working directly with HUD to address their concerns.”

Last year, Facebook turned off the ability of its advertisers to exclude racial groups from their audience of ads while it studied how the feature could be use in discriminatory ways.