The high court ruled unanimously Wednesday that law enforcement’s assumptions about privacy and mobile phones are flat wrong.

In a 9-0 decision, authored by Chief Justice John Roberts, the court said the wealth of data contained on modern cellphones could not be accessed without more traditional protections, except under emergency conditions. “The fact that technology now allows an individual to carry such information in his hand does not make the information any less worthy of the protection for which the (country’s) Founders fought,” Roberts wrote. “Our answer to the question of what police must do before searching a cell phone seized incident to an arrest is accordingly simple — get a warrant.”

The New York Times, editorializing on the decision, called it “a gratifyingly sweeping ruling.”

Truthdig legal columnist Bill Blum, who previously wrote about the cases in question, predicted the decision. Writing in April, Blum argued, “although the cases aren’t likely to force the very conservative Roberts court to overrule the pivotal 1979 decision—Smith v. Maryland—that has been cited repeatedly by the Obama administration as authority for the metadata program, they could compel the tribunal to question some of Smith’s underlying assumptions.” And so the court has.

Perhaps the most interesting aspect of Wednesday’s decision is that the justices acknowledged that their decision would protect criminals and make the job of law enforcement officers more difficult, but they decided to defend the principles of the Constitution nonetheless.

— Posted by Peter Z. Scheer