New York Times: A good ruling on privacy

The capacity of cellphones to track people's movements and provide a vivid picture of their private lives poses a substantial and growing threat to privacy.

That is why a federal appeals court ruling Wednesday restricting the government's access to location data stored by cellphone companies is so important. In a case involving a man convicted of several robberies in South Florida, the 11th U.S. Circuit Court of Appeals said law enforcement agencies could get location records from cellphone companies only if they first obtained a probable cause warrant from a judge.

The U.S. attorney's office in Miami had built a case against Quartavious Davis partly on the basis of records obtained from his cellphone company showing where he had used his phone over 67 days. The records placed him at the site of the robberies. Prosecutors got access to the data after obtaining an order from a federal magistrate judge by demonstrating that the information was "relevant and material" to their investigation, which is easier to demonstrate than probable cause.

The appeals court did not overturn the conviction because, it said, the government had acted in good faith by first obtaining a court order. But, significantly, it also ruled that "cell site location information is within the subscriber's reasonable expectation of privacy" under the Fourth Amendment, protecting people "against unreasonable searches and seizures." This ruling was based in part on a 2012 Supreme Court ruling that said placing a tracking device on a suspect's car constituted a search under the Fourth Amendment.

The decision breaks from previous appellate rulings siding with the government and ordering phone companies to provide location information under the Stored Communications Act, without a warrant. Many legal experts believe the Supreme Court will ultimately have to step in and resolve the disagreements.

Some lawmakers are not waiting for the high court to act. Maine, Minnesota, Montana and Utah, among other states, have adopted laws that require government agencies to obtain warrants to get access to historical location data from cellphone companies and to track people through their phones in real time. In Congress, Sen. Ron Wyden, D-Ore., and Rep. Jason Chaffetz, R-Utah, have introduced federal legislation that would also require warrants for location data.

As Justice Sonia Sotomayor wrote in a concurring opinion in the 2012 Supreme Court case, United States v. Jones, location data provides "a precise, comprehensive record of a person's public movements that reflects a wealth of detail about her familial, political, professional, religious, and sexual associations." Judges and lawmakers must make sure that technology is not improperly used to get around Fourth Amendment protections.