Police cannot generally search cellphones without a warrant when they are arresting someone, the U.S. Supreme Court ruled in a unanimous decision Wednesday that weighs heavily in favor of Fourth Amendment and privacy rights.
Cellphones are not the same as other physical objects, Chief Justice John Roberts wrote in the opinion. "One of the most notable distinguishing features of modern cell phones is their immense storage capacity," he wrote. "Before cell phones, a search of a person was limited by physical realities and tended as a general matter to constitute only a narrow intrusion on privacy. ... Most people cannot lug around every piece of mail they have received for the past several months, every picture they have taken, or every book or article they have read -- nor would they have any reason to attempt to do so."
But with a cellphone, "the sum of an individual's private life can be reconstructed through a thousand photographs labeled with dates, locations, and descriptions; the same cannot be said of a photograph or two of loved ones tucked into a wallet."
Because so much data can be found by searching even an inexpensive cellphone, police must in most cases obtain warrants to search them, the court ruled. "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 Founders fought. 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."
It's also the case that not all data that police could retrieve and examine on a cellphone is actually stored on the device, the ruling notes, offering an explanation of cloud computing and the legal ramifications around obtaining information stored remotely.
The ruling involved two separate cases, one from California and one from Massachusetts. In each case information obtained from police searching cellphones of the defendants led to them being charged and convicted.
In the California case, David Riley was arrested for driving with expired registration tags and it was then found that his license was suspended. His car was impounded and an "inventory search" was conducted on it, which found concealed and loaded firearms, as well as items associated with a street gang. Police seized the cellphone he had in his pants pocket, accessed information on it and saw what they thought were slang terms for members of the Bloods gang in text messages or a contacts list. After his arrest, a detective who specializes in gangs examined the phones contents to look for evidence.
Riley was convicted on weapons charges and sentenced to 15 years to life in prison after a lower court ruled that evidence seized in the cellphone search did not violate his Fourth Amendment right to unreasonable searches and seizures.
In the Massachusetts case, Brima Wurie was seen allegedly making a drug sale from a car. After he was arrested and taken to a police station, two cellphones were seized from him, one of which was receiving repeated calls from a source the phone identified as coming from "my house." Police accessed the call log, obtained the phone number and used an online phone directory to trace it to an apartment building. They then got a warrant to search the apartment where they found 215 grams of crack cocaine, marijuana, drug paraphernalia, a firearm, ammunition and cash.
Wurie was charged with distributing crack cocaine, possession of crack cocaine with intent to distribute and being a felon in possession of a firearm and ammunition. A district court denied a motion that the search of his phone was unconstitutional. He was convicted on all three counts and sentenced to 262 months in prison.
A divided panel of the First Circuit Court reversed the denial and vacated the conviction for possession with the intent to distribute and possession of a firearm by a felon. That court found that cellphones are distinct from other physical possessions that can be searched without a warrant.
In both cases, the issue before the Supreme Court was whether the warrantless searches incident to a lawful arrest were reasonable.
"These cases require us to decide how the search incident to arrest doctrine applies to modern cell phones, which 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," Chief Justice Roberts wrote.
In both cases, the cellphones in question "are based on technology nearly inconceivable just a few decades ago," when precedent-setting cases were decided.
The court examined the question of whether digital information on cellphones could be easily destroyed and therefore affect a criminal investigation and took up the matter of "extreme hypotheticals" presented in oral arguments by the U.S. government, such as the use of a cellphone by a terrorist texting an accomplice who may be about to detonate a bomb.
There are ways to keep someone from remotely wiping data from a phone or using data encryption to hide evidence, the ruling noted, and exemptions that allow for warrantless searches will continue to exist with regard to emergency situations such as that presented in disrupting a terrorist plot. In that sort of situation, a court can determine after the fact if the search met exigent circumstances that permit a warrantless search.
Law enforcement agencies have "more targeted ways" available to them to apply to individual cases, rather than warrantless searches in general, the court said.
"Finally, there is an element of pervasiveness that characterizes cell phones but not physical records. Prior to the digital age, people did not carry a cache of sensitive personal information with them as they went about their day. Now it is the person who is not carrying a cell phone, with all that it contains, who is the exception," the ruling says. "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."
The court acknowledged, however, that the ruling will have an effect on the ability of police to combat crime, but privacy must prevail.
"We cannot deny that our decision today will have an impact on the ability of law enforcement to combat crime," the ruling says. "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."
Find your next job with computerworld UK jobs