https://www.cnbc.com/2017/10/03/russian-election-meddling-gives-facebook-good-reason-to-be-afraid-commentary.html

Facebook founder and CEO Mark Zuckerberg was initially dismissive of the idea that fake news disseminated by "advertisers" via Facebook had any outcome on the U.S. presidential election. But now, he and the social media giant are clearly changing their tune.

Zuckerberg apologized recently for dismissing concerns that Facebook impacted the campaign as crazy: