Radio Shack robbery puts focus on privacy

WASHINGTON — The case that could transform privacy law in the digital era began with the armed robbery of a Radio Shack store in Detroit, a couple of weeks before Christmas 2010.

In the next three months, eight more stores in Michigan and Ohio were robbed at gunpoint.

The robbers took bags filled with smartphones. Their own phones would help send them to prison.

On Wednesday, the Supreme Court will consider whether prosecutors violated the Fourth Amendment, which bars unreasonable searches, by collecting vast amounts of data from cellphone companies showing the movements of the man they say organized most of the robberies.

Experts in privacy law said the case, Carpenter v. United States, No. 16-402, was a potential blockbuster.

“Carpenter could be the most important electronic privacy case of the 21st century,” said Jeffrey Rosen, president of the National Constitution Center, a nonprofit group devoted to educating the public about the Constitution.

In a pair of recent decisions, the Supreme Court expressed discomfort with allowing unlimited government access to digital data. It limited the ability of the police to use GPS devices to track suspects’ movements, and it required a warrant to search cellphones.

The court’s decision, expected by June, will apply the Fourth Amendment, drafted in the 18th century, to a world in which people’s movements are continuously recorded by devices in their cars, pockets and purses, by toll plazas and by transit systems. The court’s reasoning may also apply to email and text messages, internet searches, and bank and credit card records.

“The case is hugely important in that it defines the constitutional role in a really wide range of cases,” said Orin Kerr, a law professor who will soon join the faculty at the University of Southern California.