Presidential Authority to Conduct Warrantless Electronic Surveillance to Gather Foreign Intelligence Information, Congressional Research Service, January 5, 2005 [concluding that although the legality of the NSA warrantless surveillance program could not be determined due to the need for classified materials, the legal justification for the program "does not seem to be as well-grounded" as the Bush administration has asserted]. Read the full text of the report [PDF]. Reported in JURIST's Paper Chase here.