The criticism began on Thursday after a report from ProPublica, a nonprofit news site, revealed that Facebook enabled advertisers to seek out self-described “Jew haters” and other anti-Semitic topics. The company responded by saying that it would restrict how advertisers targeted their audiences on the social network.
On Friday, an article from BuzzFeed reported how Google allowed the sale of ads tied to racist and bigoted keywords, and automatically suggested more offensive terms as part of that process. By midday, Google said it would work harder to halt offensive ads.
The incidents added to a growing awareness of the complicated — and powerful — automated advertising systems that have turned Facebook and Google into two of the world’s most valuable companies. The companies have learned how to maximize their ability to connect any size of advertiser to highly tailored groups of people who use their services every day, collecting billions of dollars in the process.