''Open Fields.'' In Hester v. United States, 265 U.S. 57 (1924), the Supreme 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. Invoking Hester's reliance
on the literal wording of the Fourth Amendment (open fields are not ''effects'', the Court
ruled that the open fields exception applies to fields that are fenced and posted., in Oliver
v. United States, 466 U.S. 170 (1984). ''[A]n individual may not legitimately demand
privacy for activities conducted out of doors in fields, except in the area immediately
surrounding the home.'' Id. at 178.
An individual cannot demand privacy for activities conducted within outbuildings and
visible by trespassers peering into the buildings from just outside. 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'').
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: the proximity to the home, the presence of 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 fence surrounding home,
used for processing chemicals, and separated from public access only by series of livestock fences, by
chained and locked driveway, and by one-half mile's distance, is not within curtilage).
Naked-eye inspection from helicopters flying overhead contravenes no reasonable
expectation of privacy. Florida v. Riley, 488 U.S. 445 (1989) (view through partially
open roof of greenhouse). 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. Dow Chemical Co. v. United States, 476
U.S. 227 (1986).