Save the Constitution From Big Tech

Facebook and Twitter banned President Trump and numerous supporters after last week’s disgraceful Capitol riot, and Google, Apple and Amazon blocked Twitter alternative Parler—all based on claims of “incitement to violence” and “hate speech.” Silicon Valley titans cite their ever-changing “terms of service,” but their selective enforcement suggests political motives.

Conventional wisdom holds that technology companies are free to regulate content because they are private, and the First Amendment protects only against government censorship. That view is wrong: Google, Facebook and Twitter should be treated as state actors under existing...