At Supreme Court oral argument in the Texas social media case back in February, Justice Samuel Alito asked the question: “Let’s say YouTube were a newspaper, how much would it weigh?” In Monday’s Supreme Court opinion in Moody v. NetChoice, a five-justice majority over Alito’s objection did not directly answer that absurd question, but it did say that under the First Amendment, Facebook should get about the same amount of editorial discretion as the Miami Herald. And that’s some good news from an otherwise bleak end of the Supreme Court term. As I first explained at Slate back in February,...