https://www.theguardian.com/technology/2017/sep/21/facebook-russia-advertising-mark-zuckerberg

Facebook’s systems didn’t fail when they let Russians target American voters with divisive political messages. They worked

Mark Zuckerberg marked his return from paternity leave Thursday with a concerted effort to put lipstick on the pig of Facebook’s role in swaying the 2016 presidential election. In a Facebook live address from an earth-toned, glass-walled office, the chief executive laid out a series of steps the company will take to “protect election integrity and make sure that Facebook is a force for good in democracy”.