NSLs are issued by the FBI to individuals and businesses to obtain information about the target of a foreign intelligence or terrorism investigation. NSLs are used to obtain financial, credit, telephone, and Internet usage records. No subpoena or search warrant is required before an NSL is issued.

While NSLs have been around since the 1970s, the USA PATRIOT Act dramatically broadened the scope of their use. Under the Act, more FBI officials were empowered to issue NSLs, and the basis for justifying an NSL was lowered so that an NSL need only be "relevant" to an investigation. Statistics bear out the results of these changes. One year prior to the Act, the FBI issued 8,500 NSL requests. By 2005 that number had increased to 56,000. Librarians and others in the information industry foresaw NSLs being used to obtain Internet use records, email, search queries, and other sensitive personal information. In 2005, an NSL was issued to a Connecticut library association to obtain Internet use information.

The PATRIOT Act also imposed stringent secrecy requirements on NSL recipients. Recipients were banned from even revealing the existence of the NSL or discussing it with "any person, in perpetuity." In addition to the obvious limitations on freedom of speech, this ban also prevented any effective means to challenge an NSL in court.

In 2004, the American Civil Liberties Union, with support from library, bookseller, and publishers’ associations, challenged the PATRIOT Act’s implementation of NSLs. While that suit was underway, the NSL provisions were slightly modified by the 2006 USA PATRIOT Reauthorization Act; however, the ACLU and library claims remained.

In a 107-page opinion, federal judge Victor Marrero determined that neither the original PATRIOT Act, nor the 2006 revisions, adequately protected the constitutional rights of NSL recipients.

Judge Marrero’s opinion focused on two major points. The first point is whether the secrecy requirements went too far in restricting the speech rights of NSL recipients. The government may occasionally place restrictions on speech when they have a compelling reason and act in the least restrictive way possible. The government argued, obviously, that the restrictions were necessary to protect the security of intelligence or terrorism investigations.

However, the court found that the restrictions were a form of government censorship. By restricting the NSL recipient from "discussing anything about the NSL, even the mere fact of receipt," the result was that "the experiences of NSL recipients are excluded from the public debate." The restrictions also served as a prior restraint, which suppresses speech "in advance of its expression." Prior restraints are rarely allowed and then only for brief periods, subject to judicial review, and requiring the government to prove the need for the restraint. None of those factors are present in the PATRIOT Act.

The 2006 changes did not change the court’s perspective. The changes allowed the FBI to decide on a case-by-case basis whether to allow some disclosure of the NSL. If anything, the court was even more concerned that this change allowed the FBI to engage in "viewpoint discrimination" by forbidding disclosure when they believe that the recipient will "speak out against the use of the NSL."

The second major point in Judge Marrero’s opinion focused on provisions from the 2006 USA PATRIOT Reauthorization Act. These provisions allowed a recipient—after a period of 1 year—to petition a court to allow disclosure of the NSL. However, the provision also allowed the FBI to unilaterally certify that "disclosure may endanger the national security of the United States." The court was generally required to accept the FBI’s certification as conclusive and to reject the NSL recipient’s petition.

The court was extremely troubled by this provision. In addition to the obvious restrictions on the right of NSL recipients to obtain judicial relief, the court felt that the Act invaded the judicial branch’s constitutional power to review the acts of the executive and legislative branch. This separation of powers is an inherent part of the checks and balances that we all learned about in high school civics class and forms the foundation of our government as established by the Founding Fathers. Judge Marrero wrote, "Congress has in effect prescribed to the judiciary the standard of review a court must apply … thereby transforming judicial deference into subservience to executive judgments."

The court recognized the serious nature of the government’s security concerns and the "heavy weight" of the 9/11 attacks, noting that the New York federal courthouse sits only a few blocks from Ground Zero. But the court also noted that a similar influence of wartime "public passions, … national security, and military expediency" caused the relocation of Japanese Americans in World War II. This act was later endorsed by the courts in a decision since considered "unjustifiable."

The court could not identify a solution to these concerns within the PATRIOT Act and enjoined the entire NSL provisions from being enforced. However, recognizing the "implications of the ruling and the importance of the issues involved," the court agreed to stay its ruling pending appeal.

The court also offered some suggestions as to how the Act may be modified to pass constitutional muster. These include allowing a temporary NSL nondisclosure order, provided that the FBI either notify the NSL recipient when they can disclose information about the NSL or justify to a court the continuing need for secrecy. The NSL recipient must also be allowed to petition a court to allow disclosure or challenge the NSL.