https://www.theguardian.com/technology/2018/nov/27/facebook-warned-apparent-russian-data-trawl-2014-commons-told

After investigating claim no breach was found, Facebook says after Commons grilling

A Facebook engineer warned the company in 2014 that users apparently based in Russia were scooping vast amounts of data from the site on a daily basis, lawmakers from nine countries have been told, in heated exchanges about whether the social media company poses a threat to democracy.