The US Supreme Court returned to the bench at full strength Monday (2 October), kicking off a term in which the nine justices will decide whether or not police can obtain mobile phone metadata – including GPS location – without a warrant.

Justices are considering an appeal from Timothy Carpenter, who was convicted of armed robberies in Ohio and Michigan with the help of mobile phone location evidence police obtained from operators Sprint and MetroPCS without a warrant.

Carpenter’s attorneys argued the police violated the Fourth Amendment, which protects against unreasonable search and seizure, in obtaining the information.

The case is Timothy Ivory Carpenter versus the United States.

Privacy case overview
In briefs filed with the court, the government argued mobile phone users have “no reasonable expectation of privacy in business records created by his provider documenting the cell sites used to connect his calls.”

To back up its assertions, the government cited a 1979 court case which decided a person has “no legitimate expectation of privacy in information he voluntarily turns over to third parties”.

However, a wide variety of technology companies – including Verizon, Apple, Facebook, Google and Microsoft – disagree.

The companies in August urged the court to recognise a “new reality” in which the transfer of “highly personal information” is an inherent function of ubiquitous internet-connected devices. Though the companies were careful to note they had no position in the outcome of the case, they asked the court to “refine the application of certain Fourth Amendment doctrines to ensure that the law realistically engages with internet-based technologies and with people’s expectations of privacy in their digital data.”

“The analog-era notion that transmission of data to a third party is necessarily ‘voluntary’ conduct that precludes Fourth Amendment protection should not apply in a world where devices and applications constantly transmit data to third parties by dint of their mere operation,” the group stated in a court filing: “No constitutional doctrine should presume that consumers assume the risk of warrantless government surveillance simply by using technologies that are beneficial and increasingly integrated into modern life.”

Some states are already moving independently to update their statutes for the digital age. California in 2015 passed the California Electronic Communications Privacy Act, which requires police to get a court order before they can search for digital evidence stored on phones or company servers.