Fourth Amendment summary on exceptions to the warrant requirement.

This story (via CrimLaw) reminded me of this language:

"[T]he Court has vacillated between imposing a categorical warrant requirement and applying a general
reasonableness standard. Compare Thompson v. Louisiana, 469 U. S. 17, 20 (1984) (per curiam), with United
States v. Rabinowitz, 339 U. S. 56, 65 (1950). The Court has most frequently held that warrantless searches are
presumptively unreasonable, see, e.g., Katz v. United States, 389 U. S. 347, 357 (1967); Payton v. New York, 445
U. S. 573, 583 (1980), but has also found a plethora of exceptions to presumptive unreasonableness, see, e.g.,
Chimel v. California, 395 U. S. 752, 762–763 (1969) (searches incident to arrest); United States v. Ross, 456
U. S. 798, 800 (1982) (automobile searches); United States v. Biswell, 406 U. S. 311, 315–317 (1972) (searches of
“pervasively regulated” businesses); Camara v. Municipal Court of City and County of San Francisco, 387 U. S. 523,
534–539 (1967) (administrative searches); Warden, Md. Penitentiary v. Hayden, 387 U. S. 294, 298 (1967) (exigent
circumstances); California v. Carney, 471 U. S. 386, 390–394 (1985) (mobile home searches); Illinois v. Lafayette,
462 U. S. 640, 648 (1983) (inventory searches); Almeida-Sanchez v. United States, 413 U. S. 266, 272 (1973)
(border searches). That is, our cases stand for the illuminating proposition that warrantless searches are per se
unreasonable, except, of course, when they are not."
Groh v. Ramirez (Thomas, J. dissenting).

Justice Thomas failed to mention the good faith exception, which in practice is yet another exception to the Fourth Amendment Warrant Clause. Massachusetts v. Sheppard, 468 U.S. 981 (1984).