With over two billion users per month, Facebook is one of the most powerful advertising mediums there is. With such broad reach, targeted advertising is a necessary tool for advertisers looking to home in on the people who might good customers for their business. No harm there, right? Wrong.

Unlike traditional television marketing where audiences largely self-select into advertising sweet spots based on the specific programming, and where networks are usually frequented by specific demographic groups, Facebook’s niche marketing can be manipulated to discriminate against minority groups.

According to USA Today, the social network’s “multicultural affinity marketing” can be used to totally block access for certain groups to ads in areas like housing, credit and employment, where discrimination has historically run amok.

In response to concerns raised by black lawmakers, Facebook says it will temporarily block advertisers from excluding racial and ethnic groups. “Until we can better ensure that our tools will not be used inappropriately, we are disabling the option that permits advertisers to exclude multicultural affinity segments from the audience for their ads,” Facebook said in a letter to Representative Cedric Richmond (D-LA), chairman of the Congressional Black Caucus.

In addition to suspending advertisers’ targeting capability, Facebook will conducting an audit of how advertisers exclude groups. According to Facebook, the audit will also include the effects of affinity marketing on the LGBT community and religious groups.

Representative Robin Kelly (D-IL), a member of the Congressional Black Caucus and ranking member of the IT subcommittee, said in a statement, “Facebook’s decision to disable its multicultural affinity advertising function is an appropriate action until the serious concerns associated with that feature are remedied.”