Progress Of Science

As Justice Brandeis explained in his famous dissent, the Court is obligated -- as "[s]ubtler and more far-reaching means of invading privacy have become available to the Government" -- to ensure that the "progress of science" does not erode Fourth Amendment protections.  Here the progress of science has afforded law enforcement a powerful new tool to carry out its important responsibilities.  At the same time, this tool risks Government encroachment of the sort the Framers, "after consulting the lessons of history," drafted the Fourth Amendment to prevent.

We decline to grant the state unrestricted access to a wireless carrier's database of physical location information.  In light of the deeply revealing nature of CSLI, its depth, breadth, and comprehensive reach, and the inescapable and automatic nature of its collection, the fact that such information is gathered by a third party does not make it any less deserving of Fourth Amendment protection.

-- Chief Justice Roberts in the Supreme Court's majority opinion in Carpenter v US asserting that law enforcement needs a warrant to obtain cell phone location data, 22 June 2018