Orin Kerr writes:
This post updates readers on the current status of the mosaic theory of the Fourth Amendment. As regular readers know, that’s the novel approach to the Fourth Amendment introduced by the DC Circuit in United States v. Maynard — and then suggested by the concurring opinions in United States v. Jones — by which an aggregation of non-searches and subsequent analysis of the collected data at some point becomes a Fourth Amendment search.
There has been a lot of litigation on the mosaic theory recently. I wanted to flag three recent developments: an oral argument before the Eleventh Circuit, a decision by the Foreign Intelligence Surveillance Court, and a novel procedural step by Magistrate Judge Facciola.
Read more on WaPo The Volokh Conspiracy.