A federal judge has ruled that National Security Letters — orders from the FBI or other agencies that demand information from companies without a court order and forbid them to talk about the request — are unconstitutional. Wired reports that Judge Susan Illston has determined the letters limit freedom of speech and has ordered the government to stop issuing them or enforcing gag orders on them, though a stay of 90 days will give the government a chance to appeal. The case, involving an unnamed telecommunications company, marks the second major challenge to the statutes, raising the possibility that companies could start opening up about what's being requested about their users.

First passed in the 1980s and expanded by the Patriot Act to include more agencies and broader power, the National Security Letters statutes allow the government to request information like mobile data without having to go through a court and receive an order or warrant. The letters also include a gag order, stopping the company from acknowledging or discussing the request. Because of the ease of requesting them, they're ripe for abuse — a 2007 Justice Department investigation found that the FBI had abused the letters, issuing nearly 200,000 between 2003 and 2006, often collecting too much data or ignoring the proper rules for proceeding under the statutes.

Despite this, little information has been revealed about the letters. In early March, Google won the right to list general numbers of NSL requests, albeit in wide intervals. One previous challenge to the law by ISP owner Nicholas Merrill resulted in part of the statutes being struck down, but the government dropped its request for information and the results were never enforced. The government's inevitable appeal means we won't see the ban enforced in the near future, and there's no guarantee an appeals court will uphold the decision. But for now, it's a big win for proponents of stronger privacy laws.