Prior restraints—legal prohibitions on disseminating information before publication—are an odious burden on the freedom of expression and come with a “heavy presumption” against their constitutionality. Indeed, they are so disfavored in the law as to be virtually impossible to obtain outside of wartime. Informal prior restraints—government pressure without formal sanction—are even more unconstitutional than formal ones, as the Supreme Court noted in Bantam Books v. Sullivan (1963). In that case, the Court forbade the Rhode Island Commission to Encourage Morality in Youth from sending threatening letters to book distributors in an attempt to nudge the distributors into not carrying “obscene” material. But that strong precedent didn’t stop Cook County (Chicago) Sheriff Thomas Dart and his crusade against Back​page​.com, an online commerce site similar to Craigslist. Rather than trying to get a formal prior restraint from a court, Dart used his office, letterhead, and title to send letters threatening investigation to Visa and Mastercard (Backpage’s primary financial transaction processors) to pressure them into dropping Backpage as a customer. Dart justifies his actions by asserting that there have been “years of growth in the online sex trade,” “driving demand even higher and increasing the enslavement of prostituted individuals, including children” due to commercial sites like Back​page​.com hosting “adult services” classified ads. It worked: when Backpage sued to stop Sheriff Dart, the district court denied a preliminary injunction, accepting Dart’s claims and ruling that the public interest weighed against the website. Back​page​.com appealed to the U.S. Court of Appeals for the Seventh Circuit. As Cato, Reason Foundation, and DKT Liberty Project point out in our amicus brief before that court, Dart’s claimed “epidemic” of sex trafficking has evaded any sort of empirical verification for over two decades. Indeed, State Department data indicate that the opposite may be true. Nevertheless, Sheriff Dart, along with a new-age Baptist-and-bootleggers coalition matching the religious right and radical feminists, have raised the human-trafficking bugaboo to rally against prostitution—mimicking the drug war and all of its worst legal mechanisms. Never mind that only about 11% of Back​page​.com ads are in the “adult” section and that many ads there, whatever one may think of dominatrix services, are perfectly legal and entitled to First Amendment protection. Never mind that Backpage has fully cooperated in investigations of actual child exploitation and other noxious activity and one of the foremost experts in trafficking posits that “[s]hutting down Backpage would mean that approximately 400 persons per month would not be identified as suspicious and would thus fall off the radar screen” (because their credit-card tracking information would be lost). Courts have a responsibility to ensure that government officials, particularly law enforcement, follow constitutional constraints, and this is especially true when the results of extra-constitutional crusades can actually drive illicit behavior underground. Not unlike the recent Operation Choke Point scandal, the use of government power to pressure politically disfavored (yet legal) businesses out of the marketplace is simply un-American. To paraphrase Lord Coke’s maxim from centuries ago, the government shouldn’t be able to achieve indirectly what it’s not allowed to do directly.