"While these options have been used in legitimate ways to reach people interested in a certain product or service, we think minimizing the risk of abuse is more important. This includes limiting the ability for advertisers to exclude audiences that relate to attributes such as ethnicity or religion," Facebook's post read.

The Congressional Black Caucus first identified in late 2016 that Facebook's "ethnic affinity" marketing enabled advertisers to exclude groups of people when posting notices for housing and other services. The company vowed to block ethnic targeting for ads about residence, employment or credit, and subsequently required anyone advertising in these niches to certify compliance with Facebook's non-discrimination policy. Soon, all advertisers in the US will need to complete this certification, with a global rollout to follow.