A Russian tech executive suing BuzzFeed News for defamation has formally subpoenaed Fusion GPS, the firm that commissioned the uncorroborated anti-Trump dossier that BuzzFeed published earlier this year.Attorneys for Aleksej Gubarev, the CEO of Webzilla and XBT Holdings, disclosed in a court filing on Friday that they have subpoenaed the Washington, D.C.-based Fusion GPS as part of the suit against BuzzFeed...Gubarev is suing BuzzFeed because he and his companies are identified in the last of 17 memos that make up the dossier, which the website published on Jan. 10...In a Dec. 13 memo, the last of 17 memos that make...