When can the FBI use National Security Letters to spy on journalists? That’s classified.

[Commentary] Remember one year ago when then-Attorney General Eric Holder supposedly tightened restrictions on the Justice Department so it could not easily conduct surveillance on journalists’ e-mails and phone calls? Well it turns out the Justice Department inserted a large loophole in its internal rules that allows the FBI to completely circumvent those restrictions and spy on journalists in secrecy—and with absolutely no court oversight—using National Security Letters. And what, exactly, are the Justice Department’s rules for when they can target a journalist with a National Security Letter (NSL)? Well, according the government, that’s classified.

For those unfamiliar with NSLs, they are a particularly pernicious and controversial surveillance order that the FBI can serve on Internet and communications providers to demand all sorts of digital information without any oversight from judges or courts. Worse, NSLs almost always have a gag order attached to them, preventing the phone or e-mail companies not only from telling the target of the NSL that he or she is under surveillance but from publicly acknowledging they received an NSL at all. Various aspects of NSLs have been ruled unconstitutional in the past (including in a case still ongoing), but because of slight changes by Congress and the courts, they still persist.

[Trevor Timm is the executive director of Freedom of the Press Foundation, a non-profit organization that supports and defends journalism dedicated to transparency and accountability]