https://www.reuters.com/article/us-usa-election-social-media/u-s-may-need-new-law-to-address-russian-ad-buys-on-facebook-senator-idUSKCN1BI2X7 >U.S. legislation may be needed to require social media companies to disclose more about how their platforms are used for political advertising, a senior Democratic lawmaker said on Thursday, after new signs of Russian efforts to influence the 2016 election.