The decision of Brazil’s Supreme Court to ban the popular social media platform X (formerly Twitter) is a milestone in the saga of worldwide attempts to rein in the so-called digital town square that is shaping contemporary public life and civic discourse. That X has been blocked entirely in the world’s fourth-largest democracy, where it had 22 million daily active users, is a sign that free societies are increasingly being forced to grapple with a dilemma hitherto believed to be confined to dictatorships — how much freedom of expression should be allowed before it upends public interest and order?