* https://en.wikipedia.org/wiki/Fair_Housing_Act
* https://en.wikipedia.org/wiki/Civil_Rights_Act_of_1964
By law you cannot discriminate by any designation of protected class, which includes not only parties to a business transaction but also messaging and opportunities there upon.
I do understand why Facebook would allow ad display filtering by race and other demographic categorizations since they are a media organization who sells advertising. Whether or not that practice is morally qualified or agreeable it makes sense from a business perspective (oh how I do detest advertising).
What I don't get is why Facebook would allow ad suppliers the option to set values to these filters. Facebook has the data to make optimal demographic determinations for a geographically centered business market. Perhaps this indicates that either Facebook isn't very good at that or that ad supplies prefer to perform their own independent research out of distrust or lack of availability from Facebook.
Anyway, this does look like a valid complaint. I wouldn't just sue Facebook though. I would also seek for discovery of the ad suppliers and sue them as well. Facebook is just the proxy here. Somebody is making a deliberate determination to racial profile in violation of the spirit of the law.
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EDIT. See the third bullet point here: https://en.wikipedia.org/wiki/Civil_Rights_Act_of_1968#Types...