Two of the judges, Raymond Clevenger and Todd Hughes, sounded inclined to allow the lawsuit to continue over the objections of the Justice Department, which argued for dismissal of the case.

A Justice Department attorney, Alisa Klein, told the judges that Congress’ directions about what costs could be recovered through user fees were too vague to be the basis for a suit. She also said the alleged overcharges were impossible to calculate because surpluses in the accounts were carried from year to year, with the courts requesting appropriations to make up for shortfalls.

“That’s unknowable,” she said.

Clevenger asked, incredulously, whether the Justice Department was contending that PACER users couldn’t get refunds even if the courts incurred “knowingly, blatantly illegal” expenses on the accounts, like new curtains for the Supreme Court or “gold-plated toilets” for judges. He also raised the possibility that, under the government’s broad interpretation of the law, courts could use the PACER funds to publicize the menu in the Supreme Court cafeteria.

Klein initially resisted those hypotheticals, prompting a barbed response from the judge: “Do you have a lot of trouble answering questions in life or just when you come to the court?”

However, the Justice Department lawyer insisted that lawsuits were not the right mechanism to address even such outlandish examples. She said Congress carefully oversees the judiciary’s budget and retains the ability to address any excesses.

“Congress is presumably not going to say you can charge for the chief justice’s curtains,” Klein said.

Deepak Gupta, an attorney who argued for the PACER users, said there was no indication that Congress wanted members of the public to pay for the basic costs of the courts’ computer systems. He noted that online filing had become commonplace, but not because it makes it easier for the public to tap into that information.

“We know that this is a service that is primarily for the convenience of litigants,” Gupta said during the argument session, which lasted more than half an hour.

Gupta urged the court to rule that the court system could charge only enough to recoup the extra or “marginal” cost of providing court records to the public, but Clevenger noted that the statute doesn’t use that term.

Hughes said, “It is not a model of clarity, in terms of statutory writing,”adding: “We see this all the time, obviously.”

A federal District Court judge in Washington, Ellen Huvelle, ruled in 2018 that some of the uses the court system had made of the PACER fees were unlawful. She found that officials should not have used that pool of money to pay for online juror and victim notifications or for most courtroom technology improvements.

“The Court does not see how flat-screen TVs for jurors or those seated in the courtroom, which are used to display exhibits or other evidence during a court proceeding, fall within the statute,” wrote Huvelle, an appointee of President Bill Clinton.

If the appeals court allows the suit to proceed, it will likely be returned to Huvelle to determine what portion of the fees assessed to users between 2010 and 2016 were unlawful and how much of a refund users are entitled to.

The Justice Department or the nonprofit groups that brought the case could also appeal an adverse decision to the full bench of the appeals court or seek review by the Supreme Court.

Over the past couple of decades, the PACER system — formally called Public Access to Court Electronic Records — has vastly improved the court records from across the federal courts by making them accessible worldwide to anyone with an internet connection and the ability to pony up the fees involved.

However, at a House Judiciary Committee hearing last year, journalists, researchers and data harvesters complained that the interface is clunky, and some courts have not implemented parts of the system that are most valuable to many users.

Reformers have proposed making all the data in the system free. For the past two Congresses, Rep. Doug Collins (R-Ga.) has proposed bills that would eliminate PACER fees and make it easier to link directly to court records online.

"I support the effort to challenge the flawed PACER System, but we also must take legislative action," Collins said in a statement following the arguments Monday. "Unfortunately, the courts are operating in the shadows because the PACER System is hindering access to these records with a paywall. The Electric Court Records Reform Act, which I introduced last year, would address this issue by requiring greater accessibility through free public access to records.”

However, a judge who testified at last year's Judiciary hearing warned that nixing access fees would require a major budget increase or a dramatic hike in filing fees. He also said removing all access fees could bog down the courts’ computer systems by subjecting them to huge numbers of queries.

In the meantime, the courts’ filing database has been subject to unorthodox efforts to “liberate” the records, including one user’s failed attempt to download the entire collection . Others — with some resistance from the courts — have promoted a web tool that automatically puts the documents in a public database after a single user downloads them.

The Federal Circuit hears appeals in an eclectic set of cases, including patents and trademarks, federal employment disputes and certain money claims against the government. While located in Washington, it is a separate court from the better known U.S. Court of Appeals for the D.C. Circuit, which handles most appeals from rulings issued by federal District Court judges in the nation’s capital.

The presiding judge on the panel Monday, Alan Lourie, didn’t question the lawyers about the legal aspects of the case, so his views were harder to assess.

Lourie and Clevenger were appointed by President George H.W. Bush, while Hughes is an appointee of President Barack Obama.