• by Wendy Davis , Staff Writer @wendyndavis, November 13, 2015

Judges on a federal appeals panel suggested on Friday that Cook County Sheriff Thomas Dart took his campaign against Backpage too far when he wrote to Visa and Mastercard to demand that they stop processing payments for the online classifieds site. 

"A police official has to be very careful in what he says," 7th Circuit Court of Appeals Judge Richard Posner told Dart's attorney, Hariklia Karis.

"This is not Tom Dart as a private citizen writing a letter," Posner said. "Anybody receiving an official communication from a sheriff is going to feel that there is an implicit threat to follow this up with official action."

Posner's comments came during a 45-minute hearing about whether Backpage is entitled to a restraining order against Dart.

The online classifieds site sued Dart earlier this year, shortly after Visa and Mastercard said they would no longer process payment for transactions on Backpage.com. That move came after Dart wrote to the companies -- on official letterhead -- and asked them to stop allowing their credit cards to be used to purchase adult services ads. Dart, like many other observers, says that many of Backpage's "adult" ads are actually prostitution ads.

"If the industry has decided not to allow credit cards to be used to gamble, buy pot or watch pornography, then why allow them to be used to facilitate prostitution, even in cases of child sex trafficking?" Dart wrote in his letter. "Make no mistake: Your cards have and will continue to be used to buy ads that sell children for sex on sites like Backpage.com."

In July, Backpage sought a court order prohibiting Dart from continuing with efforts to cut off the site's funding. Backpage -- which argues that it isn't responsible for crimes committed by users -- said its business was jeopardized as a result of Dart's letters to Visa and Mastercard.

U.S. District Court Judge John Tharp in the Northern District of Illinois initially accepted Backpage's argument, but later rejected the company's position.

Among other reasons, Tharp said that Dart had a free-speech right to voice his opinion to the credit card companies. Tharp also said there was evidence that Mastercard and Visa were considering ending their relationship with Backpage before he got involved.

The appellate judges didn't appear convinced by either of Tharp's conclusions. Circuit Judge Diane Sykes told Dart's attorney that his letter "goes well beyond the expression of opinion."

"This is a cease-and-desist letter, and requires an immediate response," Sykes told Karis. "It's on his official stationery, and he's expressing himself as the sheriff of Cook County."

Dart's attorney argued that representatives from Visa and Mastercard said they didn't perceive the letter as a threat, but the judges were skeptical.

"That's ridiculous," Posner told Dart's lawyer. "These companies -- they don't feel they can defy an official with the authority that Dart has."

Dart's attorney persisted, arguing that a Visa executive said in an affidavit the company didn't perceive itself threatened.

"Well, what do you expect him to say?" Posner asked. "We're knuckling under to threats?"

Sykes added: "This is objectively threatening, whether the credit card companies will subjectively admit that or not -- and they have a public relations interest in not subjectively admitting that."