The USA PATRIOT Act (officially the Uniting and Strengthening America by Providing Appropriate Tools Required to Intercept and Obstruct Terrorism Act) was enacted as a result of the September 11, 2001, terrorist attacks on the United States. While the act is aimed at foreign terrorists, it affects all citizens' Fourth Amendment rights. The USA PATRIOT Act is a complex piece of legislation that the courts are currently scrutinizing as constitutional challenges to it arise.
Although the Act may have no effect in typical searches and seizures, it cannot be overlooked, because it can be broadly applied. For instance, one provision of the USA PATRIOT Act expands law enforcement's ability to execute searches and seizures, requiring that warrants be based only on the "significant purpose" of gathering foreign intelligence, rather than being based on probable cause. Additionally, warrants may be executed secretly on premises without notifying the owner until the search is completed. Thus, "sneak and peak" search warrants conducted under the USA PATRIOT Act do not allow an opportunity for quashing the warrant prior to its execution.