Social media is not just a vector for information. Or misinformation. It’s a place to bear witness, to express solidarity, and to fight for change. All of that is harder now than it was just a year ago. What comes next is impossible to anticipate, but it’s worth considering the possibility that the centrality of social media as we’ve known it for the past 15 years has come to an end—that this particular window to the world is being slammed shut.