Privacy

• Katz Test - Justice Harlan established a two-prong test for determining if a particular activity constitutes a Fourth Amendment search: (1) whether the individual demonstrates an actual privacy expectation; and (2) whether society would view that expectation as reasonable
  • In 2012, in United States v. Jones, the Supreme Court established an additional Fourth Amendment test to run in parallel with Katz. A Fourth Amendment violation occurs when the government intrudes physically on an area protected by the Constitution to gather information. Jones did not overrule Katz, but it did reassert the importance of the common law property lens through which the Court interpreted the Fourth Amendment pre-Katz.
• In 2001, in Kyllo v. United States, the Supreme Court considered the boundaries of what law enforcement can reasonably claim an individual has “knowingly expos[ed]” under Katz when that individual is subjected to technological means of information-gathering.
  • the Supreme Court held in Kyllo that law enforcement agents engage in a search when they obtain information using technology that enhances the senses, is not commonly used by the general public, and grants explorative access that, in the past, would have required physical entry. When law enforcement agents use such technologies, they conduct a Fourth Amendment search requiring a warrant.
• Mosaic Theory encapsulates the idea that, although individual pieces of information may be inconsequential in isolation, the information gleaned from the aggregation of such pieces is of greater significance