The dispute between Apple Inc. and federal investigators over access to a terror suspect's phone could turn on a centuries-old law that the Justice Department uses to conscript reluctant companies into service.
In a ruling unsealed Tuesday, a magistrate judge in California ordered Apple to provide software to the Justice Department to help investigators unlock a phone used by one of the suspects in the December terror attack in San Bernardino, Calif.
Apple Chief Executive Tim Cook said early Wednesday that the company would oppose the judge's order, calling it an "unprecedented step which threatens the security of our customers."
The order by U.S. Magistrate Judge Sheri Pym, was made under the All Writs Act, passed as part of a 1789 law that established the federal judiciary. Use of the law in regards to unlocking iPhones goes back to 2008, about a year after the introduction of the first iPhone. At the time, the company and investigators worked together to draft language for a court order.
The law grants federal judges broad authority to compel others to do what they say. According to a federal judge in Brooklyn, writing in an October order, it is a tool used when "the government seeks to fill in a statutory gap that Congress has failed to consider."
Courts have used the law to make phone companies help the government track and monitor customer calls, to compel landlords to turn over security videos and to force credit card companies to divulge customer records.
They have taken their cue from a 1977 Supreme Court case called U.S. v. New York Telephone Co. The majority held that the All Writs Act empowered a judge to compel the phone company to install a pen register and assist the Federal Bureau of Investigation with operating the device, which records all numbers dialed from a particular phone line.
At the time, Justice John Paul Stevens wrote in dissent that the All Writs Act should be confined to orders that enable courts to carry out their functions such as enforcing previous judgments.
"If the All Writs Act confers authority to order persons to aid the government in the performance of its duties," he wrote, "it provides a sweeping grant of authority entirely without precedent in our nation's history."
The Justice Department has sought orders under the All Writs Act compelling Apple's assistance in bypassing phone security in at least five known cases. Apple lawyers say the company has complied with All Writs Act orders in the past, without taking a position their legality.
Stephen I. Vladeck, a professor American University Washington College of Law, said the All Writs Act has no defined boundaries, and courts have yet to carve them out.
"The real question is where the line is between when the government can get an order to compel a third party to do something and when it cannot, " he said.
The company now takes the position that the All Writs Act "cannot extend as far as to compel a private company like Apple to be conscripted as an agent of the government into performing forensic services on a device in the government's possession," wrote Apple lawyer Jeffrey Landis in an October brief in one of the cases in Brooklyn.
He compared the government's use of the All Writs Act against Apple to law enforcement agents forcing a safe manufacturer "to travel around the country unlocking safes that the government wants to access."
The company has asked the Magistrate Judge James Orenstein in Brooklyn for a ruling on whether the All Writs Act can compel Apple to assist law enforcement.
A ruling by the judge could influence the court considering Apple's challenge in the San Bernardino case, as well as courts in future cases.
The case in California could move quickly through the courts. Apple can ask a federal district judge to review the magistrate judge's ruling. If Apple were to lose on review, it could then ask the Ninth U.S. Circuit Court of Appeals to consider the matter. The same process could unfold in Brooklyn, where Judge Orenstein is considering Apple's request for a ruling on the All Writs Act.
Mr. Vladeck said the stakes are so high that they could drive the government and Apple to work together for a legislative solution.
"The line here is too important to be left to judicial common law," he said.
Apple and the government weren't always on opposite sides.
Investigators approached Apple in 2008 for help in a child exploitation case in Watertown, N.Y. New York State Police needed to crack the passcode lock on an iPhone belonging to a couple who had drugged and sexually abused four children.
The company agreed to help but wanted a court's blessing first. Apple's lawyers even drafted language for the federal government to use in its request for a court order, according to court documents.
"There is no specific statute authorizing a private manufacturer of electronic media to assist law enforcement in the execution of a search warrant," federal prosecutors wrote in their Dec. 15, 2008, brief. Instead, they said, the court could approve Apple's assistance under the All Writs Act.
The judge signed the order the same day, setting a precedent that has dogged Apple and other technology companies in recent years, as they prioritized customer privacy over assistance to law enforcement.
"Apple has offered language for law enforcement to use in search warrants, but has never taken any position on whether All Writs Act orders in aid of search warrants are legally appropriate," Mr. Landis, Apple's lawyer, wrote in the Brooklyn case.
Write to Joe Palazzolo at email@example.com