The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.
“Open Fields”.—In Hester v. United States,337 the Court held that the Fourth Amendment did not protect “open fields” and that, therefore, police searches in such areas as pastures, wooded areas, open water, and vacant lots need not comply with the requirements of warrants and probable cause. The Court’s announcement in Katz v. United States338 that the Amendment protects “people not places” cast some doubt on the vitality of the open fields principle, but all such doubts were cast away in Oliver v. United States.339 Invoking Hester’s reliance on the literal wording of the Fourth Amendment (open fields are not “effects”) and distinguishing Katz, the Court ruled that the open fields exception applies to fields that are fenced and posted. “[A]n individual may not legitimately demand privacy for activities conducted out of doors in fields, except in the area immediately surrounding the home.”340 Nor may an individual demand privacy for activities conducted within outbuildings and visible by trespassers peering into the buildings from just outside.341 Even within the curtilage and notwithstanding that the owner has gone to the extreme of erecting a 10-foot high fence in order to screen the area from ground-level view, there is no reasonable expectation of privacy from naked-eye inspection from fixed-wing aircraft ﬂying in navigable airspace.342 Similarly, naked-eye inspection from helicopters ﬂying even lower contravenes no reasonable expectation of privacy.343 And aerial photography of commercial facilities secured from ground-level public view is permissible, the Court finding such spaces more analogous to open fields than to the curtilage of a dwelling.344
337 265 U.S. 57 (1924). See also Air Pollution Variance Bd. v. Western Alfalfa Corp., 416 U.S. 86 (1974).
338 389 U.S. 347, 353 (1967). Cf. Cady v. Dombrowski, 413 U.S. 433, 450 (1973) (citing Hester approvingly).
339 466 U.S. 170 (1984) (approving warrantless intrusion past no trespassing signs and around locked gate, to view field not visible from outside property).
340 466 U.S. at 178. See also California v. Greenwood, 486 U.S. 35 (1988) (approving warrantless search of garbage left curbside “readily accessible to animals, children, scavengers, snoops, and other members of the public”).
341 United States v. Dunn, 480 U.S. 294 (1987) (space immediately outside a barn, accessible only after crossing a series of “ranch-style” fences and situated one-half mile from the public road, constitutes unprotected “open field”).
342 California v. Ciraolo, 476 U.S. 207 (1986). Activities within the curtilage are nonetheless still entitled to some Fourth Amendment protection. The Court has described four considerations for determining whether an area falls within the curtilage: proximity to the home, whether the area is included within an enclosure also surrounding the home, the nature of the uses to which the area is put, and the steps taken by the resident to shield the area from view of passersby. United States v. Dunn, 480 U.S. 294 (1987) (barn 50 yards outside of fence surrounding home, used for processing chemicals, and separated from public access only by a series of livestock fences, by a chained and locked driveway, and by one-half mile’s distance, is not within curtilage).
343 Florida v. Riley, 488 U.S. 445 (1989) (view through partially open roof of greenhouse).
344 Dow Chemical Co. v. United States, 476 U.S. 227 (1986) (suggesting that aerial photography of the curtilage would be impermissible).