rulings it "took for granted such power exists" and ruled that under this presumption, "FISA could not encroach on the president's constitutional power." (2)(f) provides in part that FISA "shall be the exclusive means by which electronic surveillance, as defined in ... and the intercept of domestic [communications] may be conducted". The statute includes a criminal sanctions subpart granting an exception, "unless authorized by statute". Authorization for the Use of Military Force The Authorization for Use of Military Force was passed by Congress shortly after the 9/11 attacks. AUMF was used to justify the Patriot Act and related laws. It explicitly states in Section 2: USA PATRIOT Act Section 215 of the PATRIOT act authorized the FBI to subpoena some or all business records from a business record holder using a warrant applied for in the Foreign Intelligence Surveillance Court. Terrorist surveillance program The legality of surveillance involving US persons and extent of this authorization is the core of this controversy which includes: Constitutional issues concerning the separation of powers and the Fourth Amendment immunities The program's effectiveness and scope The legality of the leaking and publication of classified information and their implications for national security Adequacy of FISA as a tool for fighting terrorism Technical and operational details Because of its highly classified status, the implementation of the TSP is not fairly known by the public. Once Mark Klein, a retired AT&T communications technician, submitted an affidavit describing technical details known to him personally in support of the 2006 Hepting v. AT&T court case. Klein's January 16, 2004 statement included additional details regarding the construction of an NSA monitoring facility in Room 641A of 611 Folsom Street in San Francisco, the site of a large SBC phone building, three floors of which were occupied by AT&T. According to Klein's affidavit, the NSA-equipped room used equipment built by Narus Corporation to intercept and analyze communications traffic, as well as to perform data-mining. Experts from academia and the computing industry analyzed potential security risks posed by the NSA program, based on Klein's affidavits and those of expert witness J. Scott Marcus, a designer of large-scale IP-based data networks, former CTO at GTE Internetworking and at Genuity, and former senior advisor for Internet Technology at the Federal Communications Commission. They concluded that the likely architecture of the system created serious security risks, including the danger that it could be exploited by unauthorized