United States v. Jones, which reviewed the Fourth Amendment constitutionality of warrantless GPS tracking, may be the most important Fourth Amendment opinion since the Supreme Court decided Katz v. United States over four decades ago. Though Katz has dominated Fourth Amendment jurisprudence, it introduced significant ambiguities, such as the conundrum concerning whether a privacy or property model is controlling. Jones was a highly anticipated decision because it was widely understood that it might have ramifications for numerous core Fourth Amendment doctrines, including the Katz conundrum, and in turn for many governmental activities either currently or potentially subject to the Fourth Amendment. Examples include routine criminal law enforcement investigations, technological surveillance for either criminal or civil purposes (through GPS but also other means, such as location tracking capabilities embedded in individuals’ cellular telephones), and national security, to name but a few.
The attention devoted to Jones by the legal community and public at large was fully merited. The Supreme Court greatly surprised everyone by ruling unanimously that the GPS tracking at issue was subject to Fourth Amendment protections. More substantively, however, the decision resulted in three separate opinions applying vastly different rationales. This Article explains the Jones decision; situates it within the broader framework of constitutional search and seizure law; analyzes and critiques the various opinions; and explores the many varied, significant implications that Jones either will or may have for the future of Fourth Amendment jurisprudence. It makes two overarching points. First, Jones is much more important for the reasoning that the various justices employed than it is for its technically narrow holding. Second, though Jones either resolves, or suggests answers to, important questions that Katz raised, in doing so Jones itself raises significant issues for future consideration.