The FBI now issues more than 30,000 national security letters a year, according to government sources, a hundredfold increase over historic norms. The letters -- one of which can be used to sweep up the records of many people -- are extending the bureau's reach as never before into the telephone calls, correspondence and financial lives of ordinary Americans.
Issued by FBI field supervisors, national security letters do not need the imprimatur of a prosecutor, grand jury or judge. They receive no review after the fact by the Justice Department or Congress. The executive branch maintains only statistics, which are incomplete and confined to classified reports. The Bush administration defeated legislation and a lawsuit to require a public accounting, and has offered no example in which the use of a national security letter helped disrupt a terrorist plot.
Career investigators and Bush administration officials emphasized, in congressional testimony and interviews for this story, that national security letters are for hunting terrorists, not fishing through the private lives of the innocent. The distinction is not as clear in practice.