The U.S. Supreme Court earlier this week heard oral argument in two cases involving whether the police, after arresting someone, can search his or her cell phone without a search warrant. Although the police have been allowed to do a limited search of a person after they’ve been arrested, this exception to the Fourth Amendment’s warrant requirement was never intended to cover the massive amounts of sensitive information on a cell phone. But as the oral arguments made clear, the government is relying on dangerous misconceptions about cell phone technology in an attempt to justify a significant privacy intrusion.

The Issues Before the Supreme Court

After the police arrest someone, they're allowed to search the arrestee's person and the items within their immediate control without a search warrant for two reasons: first to make sure the person is not hiding a weapon that can harm officers, and second, to ensure that any evidence that could be lost or destroyed is secured. Under the search incident to arrest exception, the police do not need to make any showing that there were actual threats to officer safety or evidence destruction. That is, if the item they want to search is on the person (meaning in their pockets or purse) or within reaching distance at the time of arrest, the police get to search, period.

At issue before the Supreme Court is how this doctrine applies to the modern cell phone. Both cases involve a police search of a cell phone after they had arrested someone for a crime unconnected with the phone. In Riley v. California, the California appeals court found a warrantless search of a smartphone appropriate under the exception, ruling that the nature of the item to be searched —and ultimately the amount of information carried on a cell phone—was irrelevant to deciding whether the exception applied. But in United States v. Wurie, the federal First Circuit Court of Appeals found the breadth of information stored on a cell phone did matter and the exception didn't apply to a search of a simple flip phone. The Supreme Court had ruled in 1973 that police could search a pack of cigarettes found in an arrestee's jacket pocket and so to some extent, the issue in front of the Court now was whether a cellphone was similar enough to a pack of cigarettes that the police could search it too.

Together with the Center for Democracy and Technology, we filed amicus briefs in both Riley and Wurie, arguing that the amount of information stored on a modern cell phone is so great, that it was nothing like a pack of cigarettes and should be off limits to police without a search warrant. In other words, the technology matters for the constitutional issue before the court.

Mischaracterizing the Technological Reality

At the argument on Tuesday, it was clear that the governments of both California and the United States agreed that technology mattered for the constitutional issue too, but in a vastly different way. First, California's Solicitor General argued that when you carry a cell phone, you assume the risk that your data could be searched at any time:

But what we are saying is that people do make choices, and those choices have consequences. And the consequence of carrying things on your person has always been that if you are arrested, the police will be able to examine that to see if it is evidence of crime.

In a country where people can be arrested for not wearing a seat belt and attempts to count the number of federal criminal laws (let alone state criminal laws) have failed because there are too many to count, everyone's phone is fair game under this premise. But taking advantage of technological advancements shouldn't require a person to sacrifice constitutional privacy protection, especially when a cell phone carries far more information than any person could even physically carry on them in non-digital form.

More problematic than California's bogus assumption of risk theory was the federal government playing fast and loose with the role encryption plays in the modern world. While encryption is a universally good thing— a way to safeguard information and keep it private—the government views it as a threat.

Well, I think that there is clearly the technology available and growing technology to wipe phones remotely. But the other critical problem that comes back to Justice Ginsburg's point about getting a warrant is encryption technology is increasingly being deployed in cell phones. That is something that clearly is on the rise. And when a phone is turned off or the lock kicks in and the phone encrypts, it can be almost impossible to get into it.

This argument makes no technical or legal sense.

First, the government assumes that a specific phone actually has a lock and that it is actually deployed. But a Consumer Reports survey from last week found that only 36 percent of cell phone users have a four-digit PIN setup on their phone and that 34 percent of smartphone owners took no security measures at all. In those instances where the phone has a PIN, the government assumes a scenario where officers get the phone in the brief time frame before the phone locks. But a phone could be sitting idle in a person's pocket or next to them in a car, meaning officers wouldn't be able to bypass the PIN screen anyway.

Second, the government conflates the issue of if they can search with how they can search. If the search incident to arrest exception applies, the police are legally permitted to search the phone. But the exception does not create a right to an effective search. If the police encounter a phone they cannot access because it is locked (and they don't know the PIN) or the contents are encrypted, then the exception is simply irrelevant as to what the police can do next. They can ask the arrestee if he agrees to allow the police to search (and he can and should say no if he wants) or try to brute force their way into the phone. And as we've successfully argued elsewhere, they cannot compel the arrestee to decrypt or unlock the phone. But the incident to arrest exception has no bearing on these issues at all.

Related to this is the government's paranoia regarding the ability of a phone to be remotely deleted, a concern it consistently raised as a reason to allow police to search immediately after arrest. This paranoia is self-made. There is little empirical evidence to show that the majority of smartphones are capable of being remotely wiped. If not even a majority of Americans have a four-digit PIN on their phone, it's doubtful most people understand how to remotely wipe a phone. And it has unsurprisingly been law enforcement itself pushing to have cell phones designed with "kill switches" built in, ostensibly as a means to deter phone theft, that creates the very justification the government needs to bypass the warrant requirement. If the government were truly concerned about maintaining the integrity of a cell phone, it would make more sense for them to secure the phone instead of searching it in the field. There are plenty of ways to prevent remote wiping, whether by placing the phone in a Faraday bags, removing the battery or SIM card or powering the phone off, eliminating the justification for searching without judicial oversight.

Ultimately, this all matters because the government is using these mischaracterizations to argue for a general rule that will be applied to all phones in all arrests. If the Court accepts this argument, then police can search any phone, regardless of whether it has a PIN or encryption or no security at all. That will be the vast majority of phones the police encounter. The Court should base its ruling, which will impact millions of Americans’ cell phone privacy, on facts, not hyperbole.

During oral argument, the Court seemed to demonstrate greater awareness of the digital reality than the government. Justice Kagan remarked "people carry their entire lives on cell phones. That's not a marginal case. That's the world we live in." In a different setting, she noted that the justices might not be “the most technologically sophisticated people.” Fortunately, it doesn't take technological sophistication to figure out that the only way to protect privacy in the modern world is to prohibit the police from intruding into a cell phone without a warrant.