The U.S. Supreme Court should wait before wading into questions about how judges are using social media, the U.S. Department of Justice told the justices in a case that puts a spotlight on a California federal judge’s Twitter account.

The timber company Sierra Pacific Industries Inc. is trying to undo a $122 million settlement in part based on the argument that the trial judge’s Twitter activity—”following” prosecutors and tweeting a news story link about one of his rulings—created an appearance of bias.