What's happened: In 1978, Congress granted the FBI the authority to send national security letters to companies, asking for information about the spending habits of people suspected of being foreign spies. Cooperation was voluntary. That changed in 1986, when Congress gave the FBI the authority to make companies comply. In 1994, the scope of NSLs was expanded to include anyone who had access to classified material.
After 9/11, the Patriot Act broadly expanded the use of NSLs, this time allowing the FBI to use them to obtain information on anyone – American or not, suspect or not – if the information could be relevant to an investigation on terrorism or espionage. Individuals served with NSLs are also forbidden to tell others they received a letter, although they can appeal.
Who's affected: The number of NSLs increased from 8,500 in 2000 to 147,000 between 2003 and 2005, according to the inspector general of the Justice Department.
For it: The FBI says that NSLs are an indispensable investigative tool that can help identify suspected terrorists. "Through the use of NSLs, the FBI has traced sources of terrorist funding, established telephone and e-mail linkages that resulted in further investigation and arrests, and arrested suspicious associates with deadly weapons and explosives," FBI Director Robert Mueller told the Senate Judiciary Committee last week.
Against it: Civil libertarians say that NSLs give the FBI unconstitutional latitude to obtain a person's private information without getting proper court review. They also the NSL gag orders violate the First Amendment. A recent inspector general's report found that the FBI has misused its authority to issue the letters, has an inadequate system for collecting the requested data, and had underreported to Congress the number of NSLs issued.