Reports that two Supreme Court Justices have attended seminars sponsored by the energy giant and conservative bankroller Koch Industries has sparked a mild debate over judicial ethics.

On Tuesday evening, the New York Times reported that an upcoming meeting in Palm Springs of "a secretive network of Republican donors" that was being organized by Koch Industries, "the longtime underwriter of libertarian causes." Buried in the third to last graph was a note that previous guests at such meetings included Supreme Court Justices Antonin Scalia and Clarence Thomas, two of the more conservative members of the bench.

It's not rare for a Justice to attend a seminar sponsored by a group with judicial or political interests. Members of the court, for instances, often speak at academic institutions or think tanks. Virtually all companies, meanwhile, are affected by the judicial branch. So long as Scalia and Thomas did not participate in overt partisan activities, there would be no apparent conflict of interest.

"There is nothing to prevent Supreme Court justices from hanging out with people who have political philosophies," said Steven Lubet, a professor of law at Northwestern University who teaches courses on Legal Ethics.

But the Koch event appears more political than, say, the Aspen Ideas festival. In its own invitation, it was described as a "twice a year" gathering "to review strategies for combating the multitude of public policies that threaten to destroy America as we know it." In addition, it's not entirely clear what the two Justices did at the Koch event. A copy of the invitation that served as the basis for the Times's report was posted by the liberal blog Think Progress. It provided no additional clues. A call to the Supreme Court and an email to a Koch Industries spokesperson meanwhile were not immediately returned.

Faced with a lack of concrete information, and cognizant of Koch's fairly intense history of political involvement, legal ethicists are urging for more disclosure.

"This is certainly worth more reporting," said Stephen Gillers, a professor of law at New York University. "It is intriguing because the Koch brothers are so politically active and identify with a point of view. I know I would be curious to know exactly what forums the Justices went to. Obviously they could not go to a strategy session about how to elect more Republicans. On the other hand if it was a forum on the meaning of the First Amendment and it didn't involve strategy or fundraising a Justice could appear... It's fascinating and it merits more reporting."

What complicates the report, as Gillers notes, is that the Supreme Court, very recently, handed down a major decision on campaign finance law that Koch Industries quickly utilized. Citizens United overturned existing law by ruling that corporations could spend unlimited amounts of money on federal elections. Koch has always been an active political and philanthropic giver. And its checks have been sent to Democrats as well as Republicans (though weighted more heavily to the latter). This cycle, however, the company has become one of the premier bankrollers of conservative causes, and earned the enmity of Democrats for doing so.

Suggestions that Justices Scalia and Thomas's support of Citizens United may have been affected by their time with Koch officials ignores the fact that nothing concrete is known about what meetings they attended and when. Even then, Lubet argues, it would be difficult to argue that there is "a troublesome nexus between the event and the decision." Scalia and Thomas have been opponents of restrictions on campaign finance likely well before they were guests at a Koch Industry seminar.

But their presence at the conference still raises questions of transparency and, for some, broader concerns about judicial independence.

"I think it is very important for judges to be part of the real world and to appear in public for educative purposes to help explain the arcane mysteries of the court to the general public," said William G. Ross, a judicial ethics professor at Samford University's Cumberland School of Law. "That is very healthy and I don't think that judges should isolate themselves in a marble palace... However I am very troubled by the tendency of judges to make broader comments on public issues and to appear in public or private gatherings in which there are political overtones."

