National Security Letters in Foreign Intelligence Investigations: A Glimpse of the Legal Background and Recent Amendments [Updated March 28, 2008] [open pdf - 69KB]
From the Summary: "Five statutory provisions vest government agencies responsible for certain foreign intelligence investigations (principally the Federal Bureau of Investigation [FBI]) with authority to issue written commands comparable to administrative subpoenas. These National Security Letters (NSLs) seek customer and consumer transaction information in national security investigations from communications providers, financial institutions, and credit agencies. […] The USA PATRIOT Improvement and Reauthorization Act, P.L. [Public Law] 109-177, and P.L. 109-178, amend the NSL statutes and related law to address some of the concerns raised by critics and the courts. Following amendment, an appellate court dismissed one of the earlier cases as moot and remanded the second for reconsideration in light of the amendments. On remand, the lower federal court again held the NSLs constitutionally suspect. The decision is on appeal. A report of the Department of Justice's Inspector General [IG] found that in its early use of its expanded USA PATRIOT Act authority the FBI had 'used NSLs in violation of applicable NSL statutes, Attorney General Guidelines, and internal FBI policies,' but that no criminal laws had been broken. A year later, a second IG report confirmed the findings of the first, and noted the corrective measures taken in response. This is an abridged version of CRS [Congressional Research Service] Report RL33320, 'National Security Letters in Foreign Intelligence Investigations: Legal Background and Recent Amendments', without the footnotes, appendices, and most of the citations to authority found in the longer report."
CRS Report for Congress, RS22406