16:57, November 29 52 0 theguardian.com

2017-11-29 16:57:03
Supreme court considers limits on police tracking via mobile phone data

Justices on the US supreme court warned of “big brother” government on Wednesday as they considered limits on the police’s ability to track Americans’ movements through mobile phone data.

In a defining test of privacy rights in the digital age, justices across the ideological spectrum raised concerns over the absence of a court-issued warrant to obtain information from mobile phone companies. The nation’s highest court could potentially rule that such a practice amounts to an unreasonable search and seizure under the constitution’s fourth amendment.

“Most Americans, I still think, want to avoid big brother,” said Sonia Sotomayor, a liberal justice, invoking George Orwell’s dystopian novel about state surveillance. “They want to avoid the concept that government will be able to see and locate you anywhere you are at any point in time.”

In the case before the court, investigators obtained 127 days of phone tower records without a search warrant that allowed them to place Timothy Carpenter in the vicinity of a string of robberies of Radio Shack and T-Mobile shops in Michigan and Ohio seven years ago.

Carpenter’s bid to suppress the evidence failed and he was convicted of six robbery counts. On appeal, the Cincinnati-based sixth US circuit court of appeals upheld his convictions, finding that no warrant was required for the phone data. Carpenter is serving a 116-year prison term.

On his behalf, lawyers for the American Civil Liberties Union (ACLU) argue that police need “probable cause”, and therefore a warrant, to avoid a fourth amendment violation. The justice department contends that probable cause should not be needed to obtain customer records under the 1986 Stored Communications Act, which was updated in 1994.

But Nathan Wessler, representing Carpenter, told the court that much had changed since then: “Three-tenths of 1% of Americans had cell phones in 1986; only 9% in 1994. There were about 18,000 cell towers in 1994; today there are over 300,000.”

The surveillence potential is very different from old-fashioned tactics such as using multiple agents and cars to follow them, Wessler added. “Never could police have decided today to track me 24 hours a day, seven days a week, five months ago. That is a categorically new power that is made possible by these perfect tracking devices that 95% of Americans carry in their pockets.”

The extended 80-minute argument in Washington acknowledged how new technology is outpacing legal precedent, with phones now near ubiquitous and an associated increase in phone towers allowing ever greater precision in locating their users.

Sotomayor warned: “Right now we’re only talking about the cell sites records, but as I understand it, a cell phone can be pinged in your bedroom. It can be pinged at your doctor’s office. It can ping you in the most intimate details of your life. Presumably at some point even in a dressing room as you’re undressing. So I am not beyond the belief that some day a provider could turn on my cell phone and listen to my conversations.”

The 63-year-old justice added: “I don’t, but I know people who take phones into public restrooms. They take them with them everywhere. It’s an appendage now for some people. If it’s not OK to put a beeper into someone’s bedroom, why is it OK to use the signals that phone is using from that person’s bedroom, made accessible to law enforcement without probable cause?”

Michael Dreeben, a lawyer for the justice department, drew a distinction between direct government surveillance and data that is collected by a private company which the government can later obtain.

The government relied in part on a 1979 supreme court decision that treated phone records differently than the conversation in a phone call, for which a warrant generally is required. The court said then that people had no expectation of privacy in the records of calls made and kept by the phone company.

Sotomayor said phone companies are prevented by law from snooping on the content of a phone conversation so the same principle should apply to location data. Dreeben contended: “We’re dealing here with routing information. We’re not dealing with the contents of communications.”

Justices Samuel Alito and Anthony Kennedy appeared most receptive to the government’s argument that privacy rights do not apply when law enforcement acquires records from telecommunications providers and other companies that keep records of their transactions with customers.

Dreeben insisted: “The technology here is new, but the legal principles the court has articulated under the fourth amendment are not. The cell phone companies in this case function essentially as witnesses being asked to produce business records of their own transactions with customers.”

Alito, for example, questioned Wessler about why phone location records should be considered “more sensitive” than bank records.

Wessler agreed that bank records can be sensitive “but what [they] cannot do is chart a minute-by-minute account of a person’s locations and movements and associations over a long period regardless of what the person is doing at any given moment”.

He added: “Although police could have gathered a limited set or span of past locations traditionally by canvassing witnesses, for example, never has the government had this kind of a time machine that allows them to aggregate a long period of people’s movements over time.”

Data is gathered, Wessler noted, not only for phone calls but also text messages and data connections, including when a phone is in a pocket passively and automatically checking for new emails or social media messages or weather alerts. “Today the government is able to obtain historical cell site location information that can locate a person as precisely as half the size of this courtroom.”

Surveys show that a strong majority of Americans do not understand this information is collected and accessible, he added.

But Alito wondered: “What will happen in the future if everybody begins to realise that this is provided? If you have enough police TV shows where this is shown, then everybody will know about it, just like they know about CSI information.”

The supreme court has twice in recent years has ruled on cases concerning how criminal law applies to new technology, both times siding against law enforcement. In 2012, the court decided that a warrant is needed to place a GPS tracking device on a vehicle. In 2014, the court ruled that a warrant is required to search a mobile phone seized during an arrest.

Hi-tech surveillance can extend to purchases, subscriptions, health records, web searches and every aspect of people’s lives, the court heard. Justice Stephen Breyer said: “This is an open box. We know not where we go.”

A ruling is due by the end of June. Even if Carpenter wins, it may not matter to his conviction or sentence.

Alito pondered: “Is any of this going to do any good for Mr Carpenter?” Wessler replied: “That question is not before this court.”