On Sept. 4, the Second Circuit Court of Appeals ruled in favor of book publishers in their copyright case against the Internet Archive. The case, which narrowly involves questions of copyright and the online distribution of books, has garnered the attention of open-internet advocates and the publishing industry, but normally would not generate broad interest.

But if it heads to the Supreme Court, it would make for one of the most glaring examples of the court’s lack of enforceable ethics and recusal rules yet.

Six out of the high court’s nine justices have published books with the publishers involved in the case. Justices Sonia Sotomayor, Neil Gorsuch, Amy Coney Barrett and Ketanji Brown Jackson have all published books or signed book deals with Penguin Random House. HarperCollins has published books by justices Clarence Thomas and Gorsuch. And Justice Brett Kavanaugh is signed to a book deal with Hachette. (None of the publishers responded to requests for comment.)

The case involves a digital lending library operated by the nonprofit Internet Archive that it expanded during the early days of the COVID-19 pandemic. The publishers challenged the archive’s practice of copying and lending out digital copies of library books with no limit, through what the archive calls its National Emergency Library, as a violation of copyright that threatens authors’ earnings. A district court and the appeals court both ruled in favor of the publishers, finding that the archive’s digital lending practices violated copyright law.

The Internet Archive has not appealed to the Supreme Court yet. A spokesperson for the Internet Archive told HuffPost the nonprofit is still reviewing the appeals court decision. But if the case were to reach the high court, it would raise serious questions about the self-enforcement of conflict of interest rules by the individual justices at a time when the court has been embroiled in ethics controversies, particularly around Thomas’ receipt of gifts from friends and wealthy conservative benefactors.

As the court is bound by no enforceable code of conduct to require justices to recuse themselves when potential conflicts of interest arise, each justice is able to decide whether or not to sit on cases, including cases in which they have a financial relationship with one party. Each individual justice is guided by their personal judgment, rather than a universal rule.

This lack of defined recusal rules could create a chaotic situation if the Internet Archive case is elevated, with some justices choosing to recuse based on their financial relationships with publishers while others choose to hear the case despite their book deals.

“I don’t love the fact that we could be going into a case like this and we don’t have a clear sense of where each justice stands from an ethical perspective,” said Gabe Roth, executive director of Fix The Court, a judicial ethics watchdog group.

The self-enforcement of the court’s ethics policy enables justices to abide differently. The liberal justices Elena Kagan, Sotomayor and Jackson have in the past provided reasons for their recusals, citing the code of conduct, while the conservatives, by and large, have not. Justices Samuel Alito and John Roberts own stock in corporations ― at least once presenting an apparent conflict of interest for Roberts ― while the others do not.

In other cases involving publishers, the justices have also taken different stances on recusal. Both Sotomayor and Gorsuch chose not to recuse when the court declined to hear cases involving Penguin Random House, according to CNN. Since then, Sotomayor has indicated through the Supreme Court’s press office that she would recuse from cases involving Penguin Random House in the future. No other justice has said they would also recuse from hearing cases involving their books’ publishers.

One factor that could help determine whether a judge is conflicted: whether the justices are in an ongoing financial relationship with any given publisher. Thomas, for instance, published his memoir with HarperCollins in 2007. That may be long enough ago to not warrant a recusal, depending on how much he still receives in royalties. But the other justices all have published books or signed book deals with parties to Hachette v. Internet Archive within the past five years.

“I think those justices should recuse,” Roth said about justices with existing or recent financial relationships with the publishers.

Supreme Court ethics legislation introduced by Sen. Sheldon Whitehouse (D-R.I.) and Rep. Hank Johnson (D-Ga.) would require justices to recuse when a case comes before them involving a party with which they have had a financial relationship in the previous six years.

If that rule were implemented for the Hachette case, it would require the recusal of five justices — Sotomayor, Gorsuch, Kavanaugh, Barrett and Jackson. That would still leave four justices to hear the case, the minimum needed for a quorum.