ORIGINALLY PUBLISHED JANUARY 2021: In the months leading up to the November election, the social media platform Parler attracted millions of new users by promising something competitors, increasingly, did not: unfettered free speech. “If you can say it on the streets of New York,” promised the company’s chief executive, John Matze, in a June CNBC interview, “you can say it on Parler.”

The giants of social media — Facebook, Twitter, YouTube, Instagram — had more stringent rules. And while they still amplified huge amounts of far-right content, they had started using warning labels and deletions to clamp down on misinformation about Covid-19 and false claims of electoral fraud, including in posts by President Trump. Conservative figures, including Senator Ted Cruz, Eric Trump and Sean Hannity, grew increasingly critical of the sites and beckoned followers to join them on Parler, whose investors include the right-wing activist and heiress Rebekah Mercer. The format was like Twitter’s, but with only two clear rules: no criminal activity and no spam or bots. On Parler, you could say what you wanted without being, as conservatives complained, “silenced.”

After the election, as Trump sought to overturn his defeat with a barrage of false claims, Matze made a classic First Amendment argument for letting the disinformation stand: More speech is better. Let the marketplace of ideas run without interference. “If you don’t censor, if you don’t — you just let him do what he wants, then the public can judge for themselves,” Matze said of Trump’s Twitter account on the New York Times podcast “Sway.” “Just sit there and say: ‘Hey, that’s what he said. What do you guys think?’”