The US Supreme Court is taking up a case about privacy rights that could limit the government’s ability to track Americans’ movements in the digital age.

The justices are hearing an appeal Wednesday from Timothy Carpenter. He was sentenced to 116 years in prison after being convicted of robbing electronics stores in Michigan and Ohio. Records from cellphone towers near the stores helped place Carpenter in the vicinity of the crimes.

The big issue is whether police must get a search warrant to look at the records. Rights groups and technology experts are among those who have joined Carpenter in arguing it’s too easy for authorities to use the records to learn intimate details of someone’s life.

The Supreme Court in recent years has acknowledged technology’s effects on Americans’ privacy. In 2014, the court held unanimously that police must generally get a warrant to search the cellphones of people they arrest. Other items people carry with them may be looked at without a warrant, after an arrest.

In Carpenter’s case, authorities obtained cellphone records for 127 days.

The robberies took place at Radio Shack and T-Mobile stores in 2010 and 2011. Carpenter organized most of the robberies, in which he signaled the others in his group to enter the stores with their guns drawn, according to the government’s Supreme Court brief. Customers and employees were herded to the back and the robbers filled their bags with new smartphones. They got rid of the guns and sold the phones, the government said.

Police learned of Carpenter’s involvement after a confession by another person involved in the holdups. They got an order for cellphone tower data for Carpenter’s phone, which shows which towers a phone has connected with when used in a call. The records help approximate someone’s location.

Investigators were able to get a judge to sign an order for the records, but they had to meet a lower standard of proof than a warrant’s requirement to show probable cause that Carpenter committed a crime.

Courts around the country have wrestled with the issue. The most relevant Supreme Court case is nearly 40 years old, before the dawn of the digital age, and the law on which prosecutors relied to obtain the records dates from 1986, when few people had cellphones.

The judge at Carpenter’s trial refused to suppress the records, and a federal appeals court agreed. The Trump administration said the lower court decisions should be upheld.

The administration 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. That case involved a single home telephone.