The US attorney for the Southern District of New York threw support behind HUD's move with a statement of interest in the case.

A Facebook spokesperson reiterated the internet giant's stance in a statement to Politico. There was "no place for discrimination on Facebook," the spokesperson said, pointing out existing policies. The firm intended to respond to HUD's complaint in court.

HUD's qualms ultimately revolve around past actions. Facebook has already excluded thousands of terms from ad filtering in the years since the first concerns surfaced, and it recently forged an agreement with Washington state barring discrimination. The complaint may serve more as a reminder that Facebook's eagerness to court advertisers hasn't always factored in the social impact of its strategy.