Does the US Supreme Court's Decision on the 4th Amendment and Cell Phones Signal Future Changes to the Third Party Doctrine?

[Commentary] The US Supreme Court handed down a decision on two cases involving the police searching cell phones incident to arrest. The Court held 9-0 in an opinion written by Chief Justice Roberts that the Fourth Amendment requires a warrant to search a cell phone even after a person is placed under arrest.

The two cases are Riley v. California and United States v. Wurie, and they are decided in the same opinion with the title Riley v. California. I applaud the Supreme Court's decision.

The Court's reasoning in Riley suggests that perhaps the Court is finally recognizing that old physical considerations -- location, size, etc. -- are no longer as relevant in light of modern technology. What matters is the data involved and how much it reveals about a person's private life.

If this is the larger principle the Court is recognizing today, then it strongly undermines some of the reasoning behind the third party doctrine.

[Solove is the John Marshall Harlan Research Professor of Law at George Washington University Law School]