On June 21, 2018, the U.S. Supreme Court declined to decide the question of whether a district court judge is required to retroactively recuse himself when he allegedly follows the federal prosecutors on Twitter and, within hours after denying relief to the defendants, tweeted a link to an allegedly erroneous news article with a title implying that the defendants were liable. The relevant 9^th Circuit opinion here is U.S. v. Sierra Pacific Industries, Inc., which was published on July 13, 2017.