https://www.recode.net/2017/10/6/16438164/house-senate-investigation-facebook-russia-ads-2016-election >Congressional investigators who are studying Russia’s attempts to influence the 2016 U.S. presidential election are still missing a key tranche of evidence: The posts and other content penned by Kremlin-tied accounts on Facebook. >Earlier this month, the social giant fulfilled its pledge to turn over to the House and Senate Intelligence Committees a copy of roughly 3,000 advertisements purchased by 470 Russian-backed accounts identified on its platform. Many of those ads sought to stoke racial, religious and other social political tensions in a bid to cause political unrest in the United States, sources have said.