This article is from the archive of our partner National Journal

Privacy advocates and civil-liberties groups say the police shouldn't be able to track cell phones without a search warrant — but they're losing that fight in the courts.

Two federal appeals courts have now ruled explicitly that police don't need a search warrant to track the location of a suspect's cell phone, and a third court gave law enforcement a partial win on the issue.

It's a disturbing trend for privacy advocates, who say the law isn't keeping up with advances in technology. Retroactively tracking people's cell phones can provide an open window into almost every detail of their lives, potentially giving law enforcement far more personal information than they've ever been able to obtain before—without a warrant.

"When the government has a record of everywhere we've gone on a continuous basis over a period of time, they know our religious beliefs, our health information, our associations, our political views, our most private activities," said Susan Freiwald, a law professor at the University of San Francisco.

Yet advocates haven't been able to convince federal appeals courts that police officers should have to get a search warrant in order to obtain cell-phone records. Their latest loss came Tuesday, when the 11th U.S. Circuit Court of Appeals said no search warrant was necessary to retrace the steps of armed-robbery suspect Quartavius Davis.

After he was arrested, the police asked MetroPCS to hand over Davis' cell-phone records for the 67-day window in which the crimes were committed—including all the calls he made and received, as well as the location of the cell towers that handled those calls.

That information, though imprecise, put him close to the scene of each robbery, and Davis was ultimately convicted. (Prosecutors also had a wealth of additional evidence, including eyewitness testimony, surveillance video, and DNA.)

But privacy advocates say the police shouldn't be able to look back at such an extensive history of people's movements without first obtaining a search warrant. They say rooting through cell-phone locations, especially over a long period of time, constitutes a "search" and is protected by the Fourth Amendment's guarantee against unreasonable search and seizure.

The 11th Circuit disagreed. Davis had no reason to expect that his phone records were private, Judge Frank Hull wrote in the court's ruling—his call logs are MetroPCS' business records, not his personal property, and he must have known that when he dialed a number, he was sending information to a cell tower.

The 5th U.S. Circuit Court of Appeals reached a similar conclusion in 2013. Both courts cited a 1979 ruling that dealt with landline phones.

When a customer makes a call from the landline in his house, the court said, he might have a reasonable expectation that the content of the call is private, but not the numbers he's dialing: Everyone knows that dialing a number is transmitting information to the phone company, and those records belong to the company—not the customer.

"Cell phone users, therefore, understand that their service providers record their location information when they use their phones at least to the same extent that the landline users ... understood that the phone company recorded the numbers they dialed," the 5th Circuit said.

Privacy advocates say that reasoning is outdated, because modern cell phones record and transmit their location all the time. Cell-phone locations "give police a power they've never had in all of our history, which is essentially a time machine," said Nathan Wessler, an attorney with the American Civil Liberties Union.

Tracking phones' movements, advocates say, is more comparable to pinning a GPS unit on a suspect than it is to recording the numbers dialed from a landline phone.

Critics of warrantless phone tracking cite two Supreme Court precedents: a 2014 ruling in which the court unanimously said that police can't search a suspect's cell phone without a search warrant, and a 2012 ruling that attaching a GPS unit to a suspect's car constituted a "search" under the Fourth Amendment.

"The information that is available from location data is so revealing and its acquisition is so intrusive that it requires the protections of the warrant requirement, just like acquisition of our phone calls and our emails and our mail," Freiwald said.

Judge Beverly Martin made a similar argument in her dissent from the 11th Circuit's ruling. If information that passes through a third party is never private, she wrote, the government could obtain just about any information it wants.

"Under the majority's rule, the Fourth Amendment allows the government to know from YouTube.com what we watch, or Facebook.com what we post or whom we 'friend,' or Amazon.com what we buy, or Wikipedia.com what we research, or Match.com whom we date—all without a warrant," she wrote.

The Justice Department, however, says comparisons to GPS tracking are overblown. Identifying the nearest cell-phone tower does not give police information that's specific enough to constitute a violation of privacy, the government argues.

"Far from pinpointing the location of a car's every movement, cell-site records do not supply this kind of precise information regarding every place the cell phone user visited: they will not distinguish between a visit to a psychiatrist and a visit to the nearby mall or convenience store,' the Justice Department said in a brief to the 5th Circuit.

Following their losses in the 5th and 11th Circuits, privacy groups are hoping another case will split the circuit courts and push the issue up to the high court. And the ACLU's Wessler expects to get there "sometime in at least the next few years."

But a Supreme Court hearing is more likely when circuit courts disagree, and so far, none of them have. Cases are pending in two other appeals courts, but privacy lawyers say they've been concerned so far by the limits judges believe they're placing on their rulings.

The 11th Circuit's majority, for example, noted that Davis was using an old-school burner phone that didn't transmit his location unless he made or received a call. But its ruling probably won't be applied so narrowly, Freiwald said.

"The appellate courts are not addressing practices that I think are violating our Fourth Amendment rights regularly, and they're waiting for guidance from the Supreme Court that may never come."

This article is from the archive of our partner National Journal.

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