https://www.reuters.com/article/us-usa-trump-russia-twitter/twitter-briefs-u-s-congressional-investigators-probing-alleged-russia-role-in-election-idUSKCN1C331G >Twitter officials on Thursday briefed U.S. congressional investigators probing how Russian-backed internet trolls, bots and targeted ads may have been used on the microblogging site to influence last year's election.