On Friday, U.S. District Judge Susan Illston ruled National Security Letters (NSL) unconstitutional. In her ruling, Illston wrote that an NSL “violates the First Amendment” and the “separation of powers.” Tweet the news:

The decision is a temporary setback for the Obama administration and its claims on executive and surveillance powers. The government still has the option of appealing the ruling to a higher court within 90 days. The order also prevents the government from enforcing a gag order in any other cases right now.

In use since the late 1970s, NSLs were introduced to monitor suspected foreign spies. After the terrorist attacks of September 11, 2001 and the passage of the Patriot Act, the FBI’s latitude to issue NSLs and the scope of their authority was expanded. The FBI defines an NSL as:

“A letter request for information from a third party that is issued by the FBI or by other government agencies with authority to conduct national security investigations.”

With the expansion of its power to write NSLs, the American Civil Liberties Union (ACLU) reports that the FBI can “demand personal customer records from Internet Service Providers, financial institutions and credit companies without prior court approval.”

NSLs have also included a gag order forbidding the recipient from divulging that he or she has received it.

Fox News judicial analyst Andrew P. Napolitano has referred to NSLs as “self-written search warrants.” As an arm of the executive branch, the FBI has assumed the authority to write these warrants and thus circumvented the constitutional authority of the judicial branch.

The Electronic Frontier Foundation (EFF), a non-profit legal group that specifically defends “digital rights,” has represented an anonymous telecommunications company that was served an NSL. EFF Senior Staff Attorney Matt Zimmerman said the foundation was “very pleased” with the ruling.

Zimmerman continued:

“The government’s gags have truncated the public debate on these controversial surveillance tools. Our client looks forward to the day when it can publicly discuss its experience.”

Upon entering office, President Obama promised that his administration would be “committed to creating an unprecedented level of openness in government.” Just this week, the Justice Department celebrated “Sunshine Week,” detailing the administration’s compliance with Freedom of Information Act requests.

However, the Obama administration has repeatedly fought against the efforts of some to promote transparency. The imprisonment of former CIA officer John Kiriakou and the prosecution and treatment of Army PFC Bradley Manning may throw cold water on the image that the administration practices transparency.

Even as Judge Illston strikes down national security letters, the government still has the opportunity to appeal the ruling. However, with increased attention being given to the Obama administration’s surveillance tactics and claims of executive power, seeking and winning an appeal may be difficult.