Justice Sotomayor captured something else that we thought was fundamental. For almost two centuries the Supreme Court had said the Fourth Amendment failed to protect information that was widely shared, on the theory that people no longer had a “reasonable expectation of privacy.” Now, however, Sotomayor noted, privacy meant the ability to share information but determine who can see this information and how it will be used. She was the first justice to articulate this shift, and the big question was whether the other justices would embrace
