A judge who in 2013 declared that National Security Letters (NSLs) were unconstitutional has now changed her mind in an unsealed ruling made public Thursday.

Federal investigators issue tens of thousands of NSLs each year to banks, ISPs, car dealers, insurance companies, doctors, and others. The letters, which demand personal information, don't need a judge's signature and come with a gag to the recipient that forbids the disclosure of the NSL to the public or the target.

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The NSL brouhaha strangely isn't even about the Fourth Amendment right to privacy, as the courts have generally stated that the information sought in the letters is a business record not protected by the Constitution. Instead, the legal fight is about the First Amendment.

US District Judge Susan Illston ruled three years ago that NSLs were an unconstitutional infringement of speech. But following her ruling, the law was changed to allow the recipients of the letters in certain and very limited circumstances to disclose their existence—albeit with numerous caveats. The law's change "cures the deficiencies previously identified by this Court," Illston wrote.

The judge also pointed out that the attorney general adopted new disclosure procedures as well.

"The procedures require the FBI to re-review the need for the nondisclosure requirement of an NSL three years after the initiation of a full investigation and at the closure of the investigation, and to terminate the nondisclosure requirement when the facts no longer support nondisclosure," Illston wrote. "These procedures apply to investigations that close or reach their three year anniversary on or after the effective date of the procedures."

Under this new policy, we recently got to see for the first time what one of these NSLs looked like. Information sought in one case included a target's complete Web browsing history, the IP addresses of everyone a person has corresponded with, and records of all online purchases, according to court documents unveiled in November following a six-year fight.

The legal challenge Illston decided stemmed from a challenge brought by the Electronic Frontier Foundation, which was representing two service providers that challenged the NSLs on grounds that the gag requirement illegally limited their rights of speech.

"Our heroic clients want to talk about the NSLs they received from the government, but they’ve been gagged—one of them since 2011," EFF Deputy Executive Director Kurt Opsahl said in a statement. "This government silencing means the service providers cannot issue open and honest transparency reports and can’t share their experiences as part of the ongoing public debate over NSLs and their potential for abuse."

Opsahl said the digital rights group would appeal Illston's decision.