https://www.reuters.com/article/us-usa-trump-russia-socialmedia/social-media-firms-summoned-to-u-s-congressional-hearings-on-russia-idUSKBN1CI24Q >Representatives of Facebook, Twitter and Google have been asked to appear on Nov. 1 at hearings on alleged Russian interference in U.S. politics called by the U.S. Senate and House Intelligence Committees, officials said.