One of the creepier weapons in the arsenal of the national-security state is the “national-security letter” or NSL. It’s no ordinary letter, and it travels postage-free, but at enormous expense to the taxpayers. The FBI issues roughly 50,000 of them a year, and the Justice Department’s own internal review in 2007 concluded that many of them were issued abusively, skirting the law and internal rules. The idea is simple: the device is something like a subpoena, though it doesn’t require approval of a judge to issue. Instead, the FBI requires the recipient to help it in an investigation targeting a third party. It might be dropped on a librarian, with a demand that she tell the FBI every book that a certain subscriber checked out, every magazine he perused, and every time he accessed the Internet using a computer at the library. Or it might go to an Internet service provider, requiring information about every website viewed by a certain customer.

But the NSL also imposes a gag order on its recipient: you may not tell anyone you got this letter. On several occasions, the issuance of an NSL has been challenged by the recipient, but then the gag order applies to the litigation as well. The suit is brought by “John Doe,” and the claimant is required to keep the whole matter secret. One recipient wrote an anonymous op-ed in the Washington Post:

living under the gag order has been stressful and surreal. Under the threat of criminal prosecution, I must hide all aspects of my involvement in the case…from my colleagues, my family and my friends. When I meet with my attorneys I cannot tell my girlfriend where I am going or where I have been.

But how can long-term gag orders be reconciled with the Constitution’s protection against warrantless search and seizure and the protection of free speech and press? Judge Richard Cardamone, writing a concurring opinion for the Second Circuit in one NSL case, acknowledged that a gag order might be imposed for a short period, but he observed that “a perpetual gag on citizen speech of the type advocated so strenuously by the government may likely be unconstitutional.”

Now as a result of a partial settlement in one of several cases in which the FBI’s use of NSLs is being successfully challenged, one of the recipients has been allowed to emerge from the shadows. His name is Nicholas Merrill, a Manhattan native who ran an Internet start-up named Calyx. He was hit with an NSL demanding that he “provide 16 categories of ‘electronic communication transactional records,’ including e-mail address, account number and billing information.” That isn’t all of it—but the FBI insists that most of its requests remain secret. The FBI withdrew its NSL to Merrill in 2006, apparently after concluding it had bitten off more than it could chew. Ellen Nakashima profiles Merrill in a piece in the Washington Post:

For six years, Nicholas Merrill has lived in a surreal world of half-truths, where he could not tell even his fiancee, his closest friends or his mother that he is “John Doe” — the man who filed the first-ever court challenge to the FBI’s ability to obtain personal data on Americans without judicial approval. Friends would mention the case when it was in the news and the normally outspoken Merrill would change the subject. He would turn up at the federal courthouse to hear the arguments, and in an out-of-body moment he would realize that no one knew he was the plaintiff challenging the FBI’s authority to issue “national security letters,” as they are known, and its ability to impose a gag on the recipient.

What led Merrill to mount a challenge against the use of NSLs?

Two things, he said, “just leaped out at me.” The first was the letter’s prohibition against disclosure. The second was the absence of a judge’s signature. “It seemed to be acting like a search warrant, but it wasn’t a search warrant signed by a judge,” said Merrill. He said it seemed to him to violate the constitutional ban against unreasonable searches and seizures. The letter said that the information was sought for an investigation against international terrorism or clandestine intelligence activities. Merrill said he thought it “outlandish” that any of his clients, many of whom were ad agencies and major companies as well as human-rights and other nonprofit groups, would be investigated for terrorism or espionage.

In the view of the national-security state, however, the prohibition on warrantless searches and seizures doesn’t apply to national security matters. They’ve argued this proposition for some time, with a good deal of success—especially with judges appointed by George W. Bush, who seem inordinately beholden to the concept of national security. Although other judges have found that the Fourth Amendment can’t simply be brushed aside, the experience with NSLs is a good demonstration of how the civil liberties envisioned by the Framers are being frittered away–in the hypothetical interest of national security.