Supreme Court says government needed warrant to search cellphone tower records

Duplicate. The top post right now.

https://news.ycombinator.com/item?id=17374440

This case presents a very interesting look at the different methods of Constitutional analysis. The gist of the majority's reasoning is that under Katz (the applicable precedent addressing the scope of the Fourth Amendment), what matters is that someone has a "reasonable" expectation of privacy in the subject of the search. Katz takes a classically functional approach to the question: it looks at (the Justices' conception of) what problem the text was trying to solve, and interprets the text in that context. It concludes that location data is protected because people reasonably expect that their whereabouts from cell tracking will be kept private.

The dissent takes a textual approach. It points out that the Constitutional text says nothing about "expectations of privacy" but rather protect's a specific person's property: It protects the "right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures." As Justice Thomas points out, it is undisputed that the cell phone records do not belong to the individual. Cell phone records are information about people, not "their" information. (Just like all of the records, Google, Facebook, etc., have about you remain Google, Facebook, etc.'s private property, not yours).

This case eviscerates third party doctrine. Third party doctrine can often be described in a Katz formulation (one cannot have a "reasonable" expectation of privacy in information you have chosen to share with third parties). But more deeply, it reflects the basic textual restriction in the Fourth Amendment to protecting things that are yours (not about you). It'll have major ramifications for similar searches directed at companies like Google, Facebook, etc., and may result in courts determining that warrants are required for such data requests as well.

Here is the opinion: https://www.supremecourt.gov/opinions/17pdf/16-402_h315.pdf