486 U.S. 35 (1988)
California v. Greenwood is a foundational Fourth Amendment case addressing whether the police need a warrant to search trash left for collection outside a home.
Does the warrantless search and seizure of garbage bags left at the curb outside a home for routine collection violate the Fourth Amendment's prohibition on unreasonable searches and seizures?
Under the Fourth Amendment, there is no reasonable expectation of privacy in garbage that an individual leaves outside the curtilage of the home for collection by a third party. By exposing trash to the public and conveying it to a third party, the individual assumes the risk that its contents may be examined by others, including the police; therefore, police inspection of such trash is not a "search" within the meaning of the Fourth Amendment and requires neither a warrant nor probable cause.
No. The warrantless search and seizure of garbage left at the curb for collection does not violate the Fourth Amendment because individuals lack a reasonable expectation of privacy in trash exposed to the public and conveyed to a third party.
Greenwood is the canonical "trash" case, frequently cited for the proposition that exposure to third parties defeats a reasonable expectation of privacy. It provides doctrinal clarity on how the Katz test treats items placed outside the curtilage and entrusted to third-party collection. Practically, Greenwood authorizes routine investigative "trash pulls" to develop probable cause for warrants. The case also highlights the federalism overlay: while Greenwood sets the federal floor, several states (under their own constitutions) afford greater protection to household refuse, reminding practitioners to consider state constitutional law. For exams, Greenwood is a touchstone for analyzing the interplay among curtilage, public exposure, third-party doctrine, and the limits of nonconstitutional rules (like anti-scavenging ordinances) in defining Fourth Amendment reasonableness.