The Supreme Court of the United States handed down an important and unanimous decision today that affects just about every American citizen in the modern age of mobile technology, holding in Riley v. California (the text of the decision is here) that a law enforcement officer must first obtain a search warrant before examining the contents of a suspect’s cell phone.  Justice Roberts, who wrote the decision, accurately stated that cell phones and mobile devices “are now such a pervasive and insistent part of daily life that the proverbial visitor from Mars might conclude they were an important feature of human anatomy.”

Justice Roberts went on to state that “A decade ago police officers searching an arrestee might have occasionally stumbled across a highly personal item such as a diary…But those discoveries were likely to be few and far between. Today, by contrast, it is no exaggeration to say that many of the more than 90% of American adults who own a cell phone keep on their person a digital record of nearly every aspect of their lives—from the mundane to the intimate…Allowing the police to scrutinize such records on a routine basis is quite different from allowing them to search a personal item or two in the occasional case.”

In conclusion, the Court held that “We cannot deny that our decision today will have an impact on the ability of law enforcement to combat crime. Cell phones have become important tools in facilitating coordination and communication among members of criminal enterprises, and can provide valuable incriminating information about dangerous criminals. Privacy comes at a cost. Our holding, of course, is not that the information on a cell phone is immune from search; it is instead that a warrant is generally required before such a search, even when a cell phone is seized incident to arrest.”

I am not surprised by this decision, having had the opportunity to hear arguments on this very case as a judge for SUNY Buffalo Law School’s Wechstler Moot Court Competition earlier in the year.  I am struggling to think of another Supreme Court case from the past few years that will have such a far reaching effect on police-citizen interactions.