How Facebook Uses Ethnic Affinities to Target or Exclude People From Viewing Ads

ProPublica saw that Facebook was categorizing people based on which race they had an affinity with. ProPublica bought a Facebook ad for an event that they happened to be having about housing. They specifically clicked to exclude anyone with African-American, Asian-American, or Hispanic affinity from seeing this ad. After facing a lot of pressure from Congress and the Department of Housing and Urban Development, Facebook said it would build a new system to make sure advertisers stay in line when it comes to those ad categories.