THE RECENT DECISION by a federal judge in New York striking down the use of what are called "national security letters" represents an important judicial check on a dangerously uncontrolled FBI power. U.S. District Judge Victor Marrero's ruling might be vulnerable on appeal, but it identifies real problems in a procedure that allows the bureau to demand certain types of business records in national security investigations without a clear mechanism for court oversight and in total secrecy. Rather than appealing, the Bush administration should ask Congress to address the problems the judge identifies.

National security letters are not new, but the threat they pose to civil liberties has been growing. A form of administrative subpoena, they allow the FBI to demand from businesses records of, for example, telephone and Internet activity in counterintelligence or terrorism cases. What makes these letters unusual is their secrecy. The recipients are forbidden from disclosing that they got one, and there is no explicit provision for judicial review. Under the literal terms of the statute, a recipient would not even be able to tell his lawyer he had received it. What's more, the gag order appears to be never-ending. And their use is apparently on the rise. Congress made national security letters easier to obtain in the USA Patriot Act, relaxing the previous requirement that specific facts connect each subject to a foreign power -- though the change brought about by the Patriot Act was not at issue in this litigation. And later, Congress expanded the types of institutions that can receive them.

In defending the national security letters, the government argues that the statute implicitly allows disclosure to counsel and implicitly allows a recipient to challenge a subpoena in court. But as Judge Marrero points out, this leaves a lot of process unwritten. So even if the government is reading the law correctly -- and this seems like a stretch -- a person receiving a national security letter would have no idea that he might have rights hidden between the printed words of the statute. For all but the exceptional recipient, it will function as an unreviewable order to produce material and keep quiet. This, Judge Marrero rightly holds, cannot be squared with the Fourth Amendment, which requires that searches and seizures be reasonable. And the indefinite and unreviewable nature of the gag order threatens freedom of speech.

The problems Judge Marrero points out are fixable. If the statute already contemplates a reasonable process, making these rights explicit should cost the government little. Pending legislation, as Judge Marrero notes, could fix the problem. By adding a measure of accountability to these subpoenas, Congress could largely remove civil liberties concerns about them. Pursuing legislation -- which the Justice Department says it will do as well -- is a far better course than continuing to defend unaccountable power.