https://www.theguardian.com/technology/2017/oct/02/facebook-says-up-to-10m-people-saw-ads-bought-by-russian-agency

Ads during election and afterward focused on ‘divisive social and political messages’, says VP after company provided material to Congress

Facebook on Monday estimated that as many as 10 million people saw the political advertisements that were purchased by a shadowy Russian internet agency and ran on its platform.