It has been hailed by privacy rights activists and legal scholars as the most significant U.S. Supreme Court decision in the “digital age.” The decision was handed down on June 25 in the case David Leon Riley v. California. The case began when the police stopped Riley’s vehicle for not having a proper registration tag.


Subsequent to the stop, the police learned that Riley’s driver’s license had been suspended. The police impounded the vehicle pursuant to local departmental policy before conducting what is known as an “inventory search” of the vehicle. That search discovered two handguns.


Riley was arrested, and a search incident to a lawful arrest was conducted of his person. Pursuant to a 1969 Supreme Court decision, Chimel v. California, a lawful arrest permits the search of the arrestee to protect the safety of the officer making the arrest and to prevent possible destruction of incriminating evidence of wrongdoing. Such a search also covers the area within the immediate control of the arrested person.


Law enforcement has for years assumed in the digital age that they had the authority to search a suspect’s cell phone to detect, and possibly prevent, criminal activity. Armed with this assumed authority, the police decided to search Riley’s “smart phone” after they found evidence in the initial search of his vehicle and person that revealed he had ties to the “Bloods” street gang. Evidence discovered in Riley’s cell phone led to the State charging him with several crimes connected to an attempted murder with an assault rifle. He was convicted and sentenced to 15 years to life imprisonment.


The issue in the Riley case (and a second related case) was “whether the police may, without a warrant, search digital information in a cell phone seized from an individual who has been arrested.”


The first task before the Court was to reconcile its ultimate holding in Riley that the police cannot scour private “digital information” contained in a cell phone without a warrant with Chimel and other historical precedents law enforcement have used as a basis for conducting such searches incident to lawful arrests.


Justice Roberts, writing the lead opinion for the unanimous decision, began with this observation: Cell phones “are now a pervasive and insistent part of daily life that the proverbial visitor from Mars might conclude they were an important feature of the human anatomy.”


If not part of our physical anatomy, cell phones have certainly become the digital alter universe of our personal lives. Cell phones are probably second only to oxygen in human use. Cell phones are an integral component in virtually every aspect of human activity—from communications to sex; with as many as 12 percent of cell phone users saying they use their device while showering. Life as we know it, in this particular digital age, would come to a virtual standstill should all cell phones suddenly be silenced.


That’s why the court found it easy to say cell phones are quantitatively and qualitatively different from other things people routinely carry on their person. In fact, the court said “the term ‘cell phone’ is misleading shorthand; many of these devices are in fact minicomputers that also happen to have the capacity to be used as a telephone. They could just as easily be called cameras, video players, rolodexes, calendars, tape recorders, libraries, diaries, albums, television, maps, or newspapers.”


And the court said the single most distinguishing feature of the cell phone is its “storage capacity”—its ability to store so much about our personal, and, yes, private lives. The rule of exigent searches incident to a lawful arrest was established in a non-digital age when a physical search of someone was limited and constituted only a narrow invasion of personal privacy.


But, as the court stressed, “the possible intrusion on privacy is not physically limited in the same way when it comes to cell phones. The current top-selling smart phone has a standard capacity of 16 gigabytes (and is available with up to 64 gigabytes). Sixteen gigabytes translates to millions of pages of text, thousands of pictures, or hundreds of videos…Cell phones couple that capacity with the ability to store many different types of information. Even the most basic phones that sell for less than $20 might hold photographs, picture messages, text messages, Internet browsing history, a calendar, a thousand-entry phone book … We expect that the gulf between physical practicability and digital capacity will only continue to widen in the future.”


This kind of device, which stores so much personal information about our lives, should, and now does, enjoy a protected expectation of privacy. An arrest for public intoxication, DWI, suspected shoplifting, or driving with an expired inspection sticker should not be a license for the police to pore over all the personal and private matters stored on our cell phones. The police arresting a DWI suspect do not have a license to go to his or her home and conduct a warrantless search there and should not have a license to enter their virtual, private world.


Americans do not like warrantless searches. A Rasmussen Reports earlier this year revealed that just 24% of Americans believe the police should be allowed to conduct a warrantless cell phone search when someone is arrested. The vast majority of Americans simply do not want the police poring through their private lives stored in their cell phones. They find it both offensive and disturbing. We agree.


Will the Riley decision impact law enforcement’s ability to detect and prevent crime? Yes, but as the court pointed out, the right to privacy guaranteed by our constitution does not come cheaply. And to be fair, the damage to law enforcement will be minimal, at best. If the police find evidence of wrongdoing during the physical search of a suspect or his vehicle, they can quickly apply for, and secure, a warrant for the search of the suspect’s cell phone.


The Obama administration opposed the Riley decision, perhaps because they see it as a harbinger of the realization of the unconstitutionality of millions of warrantless searches of Americans’ communications conducted in recent years under a National Security Agency surveillance operation. Almost every law-abiding citizen now accepts the proposition that certain kinds of surveillance are necessary to maintain public safety. But the public is simply not prepared to embrace unbridled law enforcement intrusions into their personal lives under the guise of crime prevention or the monitoring, even stalking, their every movement and communication by the nation’s national security apparatus.


With Riley, individual privacy has won a major victory against the push for a militarized police state.