Jason Weinstein, a deputy assistant attorney general in the Department of Justice’s criminal division, told a panel at the Congressional Internet Caucus Advisory Committee’s ”State of the Mobile Net” conference yesterday that requiring a search warrant to obtain location tracking information from cell phones  would “cripple” prosecutors and law enforcement officials. We couldn’t disagree more.

For years, we’ve been arguing that cell phone location data should only be accessible to law enforcement with a search warrant. After all, as web enabled smart phones become more prevalent, this location data reveals an incredibly revealing portrait of your every move. As we’ve waged this legal battle, the government has naturally disagreed with us, claiming that the Stored Communications Act authorizes the disclosure of cell phone location data with a lesser showing than the probable cause requirement demanded by a search warrant. 

Since the new year, a number of significant developments has led to increased awareness on this important topic. First, the Supreme Court issued its landmark decision in United States v. Jones which held that the warrantless attachment of a GPS device on a car violated the Fourth Amendment’s right to be free from unreasonable government searches. In concurring opinions, Justices Sotomayor and Alito both noted that technology had the power to shrink privacy, particularly with respect to locational privacy, as the information gleaned from web enabled smartphones supplanted the need for law enforcement to physically install GPS devices in order to track someone. Then in March, we filed an amicus brief along with a number of other civil liberties organizations, urging the Fifth Circuit Court of Appeals to rule that cell phone location data requires a search warrant. In April, the ACLU released the results of a coordinated FOIA request that found law enforcement officials throughout the country were routinely obtaining cell phone location tracking information with differing legal methods and standards, and were frequently getting this information without a search warrant.