On October 14, the New York Post published a story alleging that smoking gun emails on Hunter Biden’s laptop implicated Joe Biden in corrupt schemes. It was immediately obvious that the story was almost certainly complete bullshit. Today, a few weeks later, it has disappeared, leaving only a noxious stink, but I want to focus on the period immediately after it was first published. Within three hours, Twitter took the most aggressive action: it banned links to the story, and redirected existing links to a landing page warning that the story violated Twitter guidelines. Facebook moved just as...