The Fourth Amendment's protections against unreasonable searches and seizures apply directly to:

Explanation

The Fourth Amendment restricts government — federal, state, and local — and does not directly bind private actors (Burdeau v. McDowell, 256 U.S. 465 (1921)). Pure private security generally falls outside Fourth Amendment scrutiny. However, this is not a license to abuse: state torts (false imprisonment, battery, defamation), California's Bane Act (Civ Code §52.1), California's constitutional privacy right (Cal. Const. Art I §1), and statutory limits like PC §490.5 all impose meaningful constraints. Guards who become 'state actors' through joint action with police or cross-deputization can face direct Fourth Amendment analysis and §1983 liability.