[JURIST] The Ohio Supreme Court [official website] ruled [opinion, PDF; press release] Tuesday that police must obtain a warrant before searching data stored in a cell phone, in the first ruling of its kind by a state high court. The court ruled 4-3 that a warrantless search of the contents of a suspect's cell phone violates the Fourth Amendment [text] prohibition against unreasonable search and seizure unless the search is necessary to protect the officers' safety or there are other exigent circumstances:

We hold that the warrantless search of data within a cell phone seized incident to a lawful arrest is prohibited by the Fourth Amendment when the search is unnecessary for the safety of law-enforcement officers and there are no exigent circumstances. Because the state failed to show that either of these exceptions to the warrant requirement applied, the search of Smith's cell phone was improper and the trial court was required to exclude from evidence the call records and phone numbers taken from the cell phone.