Longtime reporters who cover the NSA know that any time we ask the obstinate spy agency for information, we're probably going to hit a brick wall. But who would have thought that trying to obtain information about information the agency has already given us would lead to the same wall?

That's what happened when the Federation of American Scientists filed a FOIA request with the Defense Department (of which the NSA is a part) earlier this year seeking information about any authorized leaks of intelligence made to the media during the previous 12 months.

The response they got (.pdf) from the National Security Agency might well have come from Winston Smith's Ministry of Truth.

"The document responsive to your request has been reviewed by this Agency as required by the FOIA and has been found to be currently and properly classified in accordance with Executive Order 13526," the letter read. "The document is classified because its disclosure could reasonably be expected to cause exceptionally grave damage to the national security."

Last year, Congress amended the Intelligence Authorization Act to require government officials to notify lawmakers whenever they disclose national security secrets to the media as part of an "authorized" leak. Under Section 504 of the statute (.pdf), the government official responsible for authorizing the disclosure has to submit to congressional intelligence committees a timely report about the disclosure, if the information is classified at the time of the leak or was declassified for the purpose of making the leak, and if the information being disclosed was "made with the intent or knowledge that such information will be made publicly available."

There have been numerous authorized leaks over the years, including the controversial White House leaks about the killing of Osama bin Laden. There have been even more unauthorized leaks, however—by government officials and workers. It makes sense for Congress to want to know when classified information has been leaked or declassified in order to distinguish official leaks from unauthorized ones. Lawmakers on the intelligence committees look silly when they tell reporters they can't talk about something, while government officials are freely yapping about the same topic behind their backs. They also look silly when they publicly call for a criminal investigation into a leak that turns out to have been authorized. And, of course, members of both parties in Congress want to know when the party in power in the White House might be authorizing leaks for political gain.

But once those leaks are made to the media and published, why shouldn't the public also be able to know when the information came from an authorized source or an unauthorized one?

Steve Aftergood, director of the Federation of American Scientists' Project on Government Secrecy, noted in his letter to the NSA appealing its response (.pdf) that "It is well established that information, including classified information, that has been publicly disclosed on an authorized basis loses its exemption from disclosure under FOIA."

He has a theory, however, about why the NSA might not want to disclose what it has disclosed. He says that even though the statute refers to information that the leaker expects will be made public, the NSA might not want the public to know which information was part of an authorized leak because some might have been provided off the record.

"I think it’s more likely that these disclosures were part of a negotiation with news organizations," he told WIRED. In that case, "the disclosures in question were not actually published, rather they were part of a dialogue with a reporter perhaps in an effort to dissuade her or him from publication."

The very notion of an authorized disclosure of classified information is, of course, a bit of an oxymoron, Aftergood notes in a blog post about the issue. "If something is classified, how can its disclosure be authorized (without declassification)?," he writes. "And if something is disclosed by an official who is authorized to do so, how can it still be classified?"

Only Winston Smith knows.