Meta literally facilitated genocide in Myanmar as well as sex slavery by failing to properly screen ads and in some cases didn't even have anybody who could read the language they were in.
[1] https://www.forbes.com/sites/kashmirhill/2014/07/10/facebook...
[2] https://www.cnet.com/tech/services-and-software/a-look-at-bo...
[3] https://www.newsweek.com/facebook-racial-ad-targeting-multic...