The question of whether a police officer can review the contents of the cell phone of the person he arrested is before the United States Supreme Court and according to reports, the Justices are having some trouble with the concept.
Search and seizure cases do not get as much press as other constitutional law cases. Most folks figure they will never face the issue, and therefore, the issue does not concern them.
But consider this scenario - a police officer arrests you for jaywalking, or for not wearing a seatbelt. Should the police be able to take your phone and look at every single email that you have written, including work emails, including emails to family members, very intimate communications. Should he be allowed to review your bank records, your medical data, your calendar, and your GPS history?
The case is being considered at the “the tax return of the jaywalker” case. and it seems to me that the Court needs to limit the ability to search the phone without a warrant. And if they can search the phone, how about your tablet? Your laptop?
More details are available at the New York Times - Justices Appear Divided on Cellphone Warrants.