Does all police observation activity constitute a search?
A. No. To constitute a search triggering Fourth Amendment protections, Katz requires a subjective expectation of privacy (some action or activity manifesting a purpose to keep the property or activity sough to be protected private) and a determination that the privacy expectation is objectively reasonable. For example, dog sniffs of the exterior of luggage in an airport does not constitute a search, United States v. Place, nor does an examination of trash left outside the curtilage of a home. California v. Greenwood.
