The USA Patriot Act of 2001 amended the Foreign Intelligence Surveillance Act (FISA) to allow the government to undertake broad-based surveillance of subjects within the United States if the government certifies that a “significant purpose” of the surveillance is to obtain foreign intelligence information. This replaced the previous, more stringent requirement that obtaining foreign intelligence information be the “primary purpose” of the surveillance. The District Court held that these amendments violate the Fourth Amendment by allowing the government to conduct traditional criminal surveillance without satisfying any probable cause requirement.
Mayfield v. United States, Civil No. 04-1427-AA (D. Or. Sept. 26, 2007)