Within the next week, the U.S. Supreme Court is scheduled to decide on a pair of cases that will have major implications for the over 91 percent of Americans who carry a cellphone. At issue is the question of whether police officers are legally allowed to search through the contents of someone’s phone—that is to say, much of a person’s private life—without first obtaining a warrant.

The roots of this battle extend back to 1969, when the Supreme Court ruled in Chimel v. California that, upon making an arrest, police are allowed to search a suspect and ‟the area into which he might reach.” The logic was to protect officers by giving them a chance to discover any weapons the suspect might use against them and to guard against the destruction of evidence.

Since the advent of cellphones, the devices we keep in our pockets have been swept up in the category of items—which have long included wallets and notebooks—that police could legally search without a warrant. However, as cellphones have evolved into smartphones, the amount of information that a law enforcement official could learn just by skimming through someone’s phone has increased exponentially.

Depending on what apps a person has installed, digging through a suspect’s smartphone could give law enforcement information about every one a suspect has called, the contents of her text messages, everything she’s ever posted on social media, the location of every place to which she’s looked for directions, her medical history, a detailed picture of her financial situation, on and on.

To police looking to obtain much of this information, if it weren’t contained on a phone the suspect was carrying with them at the time of arrest, a warrant would be required. But, since all of that data is now contained on small, glowing rectangle that’s rarely more than a few feet from a person’s body, the law enforcement’s ability to access it without first having to justify their need to do so before a judge raises some very troubling questions about violations of Fourth Amendment protections against unreasonable search and seizure.

At the same time, all of that information is an invaluable asset to law enforcement. And without this ability to search phones on the spot, justice officials argue that, in the time required to go out and get a warrant, suspects will have wiped all of the relevant data from their phones.

The Supreme Court heard back-to-back oral arguments for two key cases pertaining to the warrantless search of cellphones in late April.

The first case is Riley v. California, which stems from an arrest made in the summer of 2009, when college student David Leon Riley was pulled over in San Diego for driving with expired registration tags. Police searched Riley’s car and turned up a pair of handguns that laboratory tests revealed were used in a gang-related shooting two weeks prior.

Riley was arrested and his cellphone was confiscated by officers who looked through it on two separate occasions, neither time with a search warrant. The phone contained pictures of Riley standing next to a red Oldsmobile that looked a lot like the one involved in the shooting. It also contained videos of him making gang signs. With this evidence in hand, police obtained the phone’s geolocation data and discovered that Riley had been in the area of the shooting around the time it occurred.

Riley was put on trial for attempted murder, among a host of other charges, even though there weren’t any witnesses who could physically put him at the scene of the shooting. Riley’s lawyers attempted to block evidence from the phone search from being introduced in court, but the motion was refused. After one mistral, Riley was convicted and sentenced to 15-years-to-life in prison.

Riley contested the decision, but it was upheld by an appeals court before being taken up by the highest court in the land.

While the device in question in Riley is a smartphone, the flip phone in the second case, United States v. Wurie, is decidedly less high tech—although the issues raised by the case are otherwise quite similar.

In September of 2006, police witnessed Brima Wurie sell drugs to another man on a Boston street corner. Wurie was arrested and his phone was taken by police. While Wurie was in custody, his phone repeatedly received phone calls from a number identified as ‟my house.” Without obtaining a warrant, officers looked at the call log and linked the “my house” number with a physical address. Wurie told police he didn’t live at that address, but the officers involved didn’t believe him. Instead, they believed that he had hidden a stash of crack cocaine at the house. They got a warrant and searched the premises, discovering both firearms and illegal drugs.

Wurie was charged and convicted on three different counts. However, two of those charges were later overturned by an appeals court that ruled the officers’ warrantless search of Wurie’s phone violated the Fourth Amendment.

A litany of groups from the across the political spectrum have chimed in with amicus briefs arguing against the ability of police to search phones without warrants. Breifs have been submitted by a coalition of media organizations including the New York Times; the left-leaning American Civil Liberties Union; and the conservative Cato Institute, which was founded by right-wing billionaire Charles Koch.

“Smartphones could not have been in the minds of the Framers when they wrote the Fourth Amendment to protect ‘persons, houses, papers, and effects, against unreasonable searches and seizures,'” reads the media organizations’ brief, “but the information contained in these devices falls squarely within the amendment’s purpose.”

Conversely, the U.S. Department of Justice, which unsurprisingly supports law enforcement in both cases, has argued that smartphones make it easy for criminals to quickly dispose of incriminating data they’re afraid law enforcement might later see. Text messages can be deleted; apps can be uninstalled; phones can even be remotely wiped of all user data with apps like Find my iPhone.

The United States isn’t the only country currently dealing with the issue of cellphone searches. The Supreme Court of Canada is also in the process of deciding on a case stemming from the 2009 arrest of a Toronto man for robbing a jewelry stall at a flea market. Police searched the man’s phone and discovered pictures of guns and cash, as well as text message about jewelry. That information was used in the man’s prosecution. His lawyer objected and, last year, The Court of Appeal for Toronto ruled that it’s acceptable for police to search a suspect’s phone without a warrant if information on the device isn’t password protected.

While Canada’s highest court has agreed to hear an appeal on the case, the U.S. court may follow the lead of the Ontario court and strike some sort of compromise.

It’s possible the court will opt to restrict law enforcement’s ability to search a phone depending on the severity of the crime for which the suspect is being accused. There may be little justification for going through the text messages of someone who was jaywalking or loitering, but doing so for a person suspected of smuggling guns or dealing large quantities of illegal narcotics might be acceptable.

A another possible compromise could come in the form of allowing warrantless phone searches, but limiting the types of data that could be legally accesses to only the bits that are reasonably believed to contain evidence of a crime. However, this type of decision could easily prove problematic because it’s difficult for a officer to determine ahead of time where on a cellphone to look for a specific piece of data—especially if they don’t know exactly what is they’re searching for until they see it.

As Chief Justice John Roberts asked during the case’s oral argument earlier this year, ‟If you’re arresting someone on suspicion of being a gang member, what part of the cellphone is not likely to be pertinent evidence?”

During that same session, Justice Elena Kagan worried that, because modern phones allow people to essentially carry a record of their whole lives in their pockets, and police searches can be triggered by almost any reason, significant invasions of privacy could could be triggered by comparatively minor transgressions. She said it was possible that someone would be pulled over for driving without a seatbelt to have every single email, text message, and event on their calendar exposed to police scrutiny.

‟That strikes me as a very different kind of world than the kind of world where somebody has pictures of their family in a billfold,” Kagan said.

California Solicitor General Edward DuMont, arguing on behalf of the state in Riley, said that allowing police to look through the contents of a phone could also help ensure officer safety. DuMont cited an incident where an officer pulled over a car and then became much more alert after looking through a suspect’s phone and seeing pictures of him holding weapons. He added that potentially forfeiting their right to informational privacy is something that people may ultimately have to accept as facet of modern life.

‟People make a choice when they carry their cellphones with them,” DuMont said, ‟and should have no expectation of privacy if they are arrested.”

The court’s decision on both cases is expected some time before June 30.

Photo by Intel Free Press/Wikimedia Commons (CC BY 2.0)