“Section 215 [of the Patriot Act, signed into law on October 26, 2001] allows business records and computer hard drives of United States citizens and noncitizens alike to be searched in the name of a terrorism investigation and, like the new wiretap law, gags people from informing anyone of such monitoring: ‘No person shall disclose to any other person (other than those persons necessary to produce the tangible things under this section) that the Federal Bureau of Investigation has sought or obtained tangible things under this section.’ Included as ‘tangible things’ are records held by public libraries. …To obtain such records, the government need only certify that the target is part of a foreign intelligence investigation and does not have to submit any sort of proof that the target is in any way a foreign agent.”
– Stefan Halper and Jonathan Clarke, America Alone, Pages 288-289