What doesn't your cellphone know about you? Chances are the mobile phone in your pocket carries a staggering amount of personal information — so much so that, should you ever be arrested, the police will need a search warrant to look at the data stored within.
That's the gist of the landmark ruling the Supreme Court handed down today (June 25) in the case of Riley v. California, combined with the separate case of U.S. v. Wurie. This means the police's right to search a suspect under arrest does not extend to the data on mobile phones.
In identifying cellphones as fundamentally different from other common possessions, the Supreme Court's decision may affect other digital devices such as tablets, laptops and wearable devices such as Fitbits or Google Glass. It cloud also be used more broadly to argue that the law should treat digital devices differently from analogue ones.
"The Court is starting to catch up and recognize how technology interacts with our constitutional protections," said Hanni Fakhoury, staff attorney at the Electronic Frontier Foundation in San Francisco.
The unanimous 9-0 ruling is a big win for privacy advocates, but a setback for law enforcement, who must now obtain a specific warrant in order to examine the data on a specific cellphone.
"We cannot deny that our decision today will have an impact on the ability of law enforcement to combat crime," Chief Justice John Roberts wrote in the majority opinion. However, law enforcement can still confiscate the phones and hold them while a warrant is obtained.
"The Department will work with its law enforcement agencies to ensure full compliance with this decision," Ellen Canale, a spokesperson for the US Department of Justice, told Tom's Guide. "We will make use of whatever technology is available to preserve evidence on cell phones while seeking a warrant, and we will assist our agents in determining when exigent circumstances or another applicable exception to the warrant requirement will permit them to search the phone immediately without a warrant."
During the case, the U.S. government tried to argue that cellphones should not be treated differently from other objects found on an arrested supect's person, such as wallets, purses or address books.
The Supreme Court's decision rejected this argument outright, with Roberts writing that comparing a cellphone to a wallet "is like saying a ride on horseback is materially indistinguishable from a flight to the moon."
"Cellphones differ in both a quantitative and a qualitative sense from other objects that might be carried on an arrestee's person," the Supreme Court's opinion reads. "Before cellphones, a search of a person was limited by physical realities and generally constituted only a narrow intrusion on privacy. But cellphones can store millions of pages of text, thousands of pictures, or hundreds of videos."
"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," Roberts wrote. "Our answer to the question of what police must do before searching a cellphone seized incident to an arrest is accordingly simple — get a warrant."
So you've been arrested...
When police arrest someone, they can search the arrestee's person, as specified under the Search Incident to Lawful Arrest doctrine, by patting him or her down in a search for weapons, drugs or other incriminating evidence. They can also seize the arrested person's cellphone (or tablet or laptop) and hold onto that device.
However, because of today's Supreme Court ruling, the police can no longer access that cellphone and the data on it without a search warrant. It doesn't matter whether the phone is protected by a passcode or lockscreen.
"[The police] can seize your cellphone and hold onto it, but they can't just say, 'Because we've arrested you, we're going to search the cellphone,'" explained Fakhoury.
However, the Supreme Court decision allows for exceptions. For example, if police believe that evidence on a phone is in immediate danger of being remotely destroyed, or if someone is in immediate danger, officers can search a confiscated phone on the spot — but they will have to provide evidence that their actions were necessary at a later hearing.
Yet police officers can't simply justify an immediate search with the argument that "someone might remotely delete the data on this phone before we get a warrant."
During the Supreme Court hearing of Riley v. California, the government made the case that, because the data on many smartphones can be remotely wiped, police would need to be able to search all confiscated cellphones as soon as possible in order to avert the risk of evidence being tampered with or destroyed.
"The Supreme Court rejected that," Fakhoury explained. "[They] said 'No, you don't get a bright-line rule [i.e. a clearly defined standard]. You can show in individual circumstances ... that have to be based on probable cause that evidence was going to be destroyed.'"
Police — and cellphone thieves — do have means of preventing phone owners from remotely deleting data, such as by placing confiscated phones in a Faraday bag or cage to block wireless reception, or by removing the phone's battery or SIM card. Roberts' opinion recognizes these methods as legal.
Cellphones that are seized as part of broader search warrants are still fair game for search. Police can examine the scene of a crime, or the interior of a home or office for which they have a search warrant, and confiscate any and all evidence — including electronic devices. For example, if police officers carry out a drug bust and see a computer with child pornography visible on the screen, they can confiscate the computer.
So the police have a warrant...
Say the police do get a warrant for your mobile phone. What then?
Fakhoury said that such a warrant would probably give the police access to just about anything on that cell phone, including text messages, call logs, email messages and conversations with other people, even if the police don't have a warrant for that other person.
The warrant would probably also includes any data stored in a cloud service and accessible from that phone, even though that data is technically not on the phone.
But what if you have a passcode set on your phone, or some or all of the data on your phone is encrypted? The police can ask you to divulge your password or decryption key, and if you do so willingly you have legally consented and any information the police uncover is legally admissible.
What if you don't divulge your passcode or decryption key?
"That's the next level of this debate, and it doesn't touch on the Fourth so much as the Fifth Amendment," Fakhoury said.
While the Fourth Amendment governs rules of search and seizure and was at the heart of today's Supreme Court decision, the Fifth Amendment governs rules of legal process and, among other things, gives anyone the right to refuse to testify against himself or herself.
"We have argued that [the police] cannot compel you [to divulge your passcode]" Fakhoury said, citing a 2012 decision by an Eleventh Circuit federal court that ruled that the Fifth Amendment protects citizens from being forced to decrypt their hard drive contents.
Separate but related cases
Riley v. California actually combines two separate but combined cases. The first deals with David L. Riley, who in 2009 was pulled over for a traffic violation in San Diego. Police found loaded guns in Riley's car, then seized his smartphone and found evidence on it connecting Riley to a street gang and a prior shooting. The smartphone evidence was used to convict him, and state courts upheld the conviction, which was reversed by the Supreme Court today.
The second case, United States v. Wurie, deals with a 2007 incident in which Boston resident Brima Wurie was arrested on drug and gun charges. The police accessed the call log on Wurie's flip phone and used the logged calls to connect Wurie to a crack house, but the log was later thrown out by a federal appeals court. The government appealed that decision to the Supreme Court, which upheld the appeals court's decision today.
Possible widespread effects
The Riley decision could redefine what the law understands as a reasonable expectation of privacy. By treating digital devices as fundamentally different from the physical objects they replaced, such as wallets and address books, the Supreme Court is acknowledging that digital devices contain exponentially more information than physical objects, and that this difference in scale is constitutionally important.
By basing their decision on that difference in scale, Fakhoury said the justices' unanimous opinion contains "some very good language" about protecting American citizens' privacy in the digital age. It might even be used to argue against the National Security Agency's ability to broadly collect massive amounts of metadata on the telephone conversations of American citizens, Fakhoury suggested.
"There's a difference between capturing one person's phone calls over three days, and capturing everyone's phone calls over five years," Fakhoury said. "That difference in scale is constitutionally significant."
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Jill Scharr is a creative writer and narrative designer in the videogame industry. She's currently Project Lead Writer at the games studio Harebrained Schemes, and has also worked at Bungie. Prior to that she worked as a Staff Writer for Tom's Guide, covering video games, online security, 3D printing and tech innovation among many subjects.