The shadowy Foreign Intelligence Surveillance Court has appointed its first “friend of the court” to add an outsider’s perspective to the highly secretive process of approving surveillance requests from the government.

Preston Burton, a criminal defense attorney known for his work with accused spies, is the first of at least five amici curiae the court must appoint due to a provision in the USA Freedom Act, the surveillance-reform legislative package passed in June.

Groups like the Center for Democracy and Technology had pressed Congress to include language about amici, or independent experts, to provide the court with unbiased understanding of the complex technical and civil-liberty issues that come before it.

The role of the amici is fairly limited, however. They will only be brought in on “certain matters” that may present “a novel or significant interpretation of the law.” The FISA Court does not necessarily have to share classified information with the amici, and has the authority to determine whether or not information they present is “relevant.”

Burton is best known for representing famous clients, including Monica Lewinsky, the so-called D.C. Madam, and several former FBI, CIA, and DIA agents accused of being spies for foreign countries.

It’s unclear why he was chosen to represent the public’s interest in this way. In 2006, Washingtonian described him as “still the man to see if you’re a spy.”

One factor could be that in espionage cases, defense attorneys are required to have security clearances — something that is also required of amici for the FISA Court.

By contrast, most civil liberties activists don’t have security clearances, and wouldn’t accept the non-disclosure prohibitions that go along with them.

Judge Michael Mosmon, the author of the order, wrote that Burton is “well qualified to assist in the Court in considering the issue specified herein.”

Reached by The Intercept, Burton said he doesn’t comment on matters that are pending in court.

Some privacy advocates are wary.

“Without an institutional base and with all the secrecy obligations at FISA there is a very serious risk of ‘capture,’” wrote Jeramie Scott, national security counsel for the Electronic Privacy Information Center. “He will need to be extremely independent to safeguard all of the interests that role requires.”

Photo caption: Preston Burton in his office.