ON MARCH 28th the American government sued Facebook for allowing advertisers to exclude whole categories of people from seeing ads for housing—couples with children, non-Americans, non-Christians, disabled people, Hispanics, and so on. The Department of Housing and Urban Development (HUD) said this violated the Fair Housing Act, which bans discrimination against certain “protected” groups.

Facebook has tried to clean up its act, shutting down tools which allowed advertisers to aim at Facebook users based on age, gender, and zip code. HUD is seeking “appropriate relief” for Facebook’s past actions nonetheless. HUD’s lawsuit also accused Facebook itself of discrimination against minorities through the algorithms it uses to run its advertising business. These are the same ones that Facebook uses to maximise click-throughs and views, and therefore revenue.