Once Searched, Forever Seized?

How private is the data on your cell phone? That was the big question before the Supreme Court last week in a pair of cases, Riley v. California and United States v. Wurie, with the potential for huge consequences for the future of information privacy.

The cases involve a longstanding exception to the Fourth Amendment that permits the police to search items on or near someone they have arrested, no warrant required. The rule was intended to keep officers safe and prevent the destruction of evidence. In recent years, however, the rule has given police free rein to seize and search the devices that store our calls, text messages, e-mails, and troves of other personal data such as our financial history, medical information, and daily movements.

Many of the Justices expressed concern over the disproportionate invasion of privacy, suggesting that a warrant should be required for a cell phone search. But there was another question that caught the Court’s attention: What happens to all that data once the police have it?

It is common practice to copy the contents of device before searching it. But if the police don’t need a warrant to do that, then there is also no judicial check on what happens to that information, how it’s used, or who gets to see it. A warrant requirement would serve two purposes. It would be a bulwark against highly invasive fishing expeditions resembling the “general warrants” so abhorred by the nation’s Founding Fathers. And it would provide a way to limit the sensitive information that the government is allowed to keep and share about you.

The retention of cell phone data raises extraordinary privacy concerns above and beyond whatever visual inspection a police officer might need to conduct on the spot. In the Riley case, for example, a San Diego detective admitted to downloading “a lot of stuff” from the cell phone at a regional computer forensics lab run by the FBI. The lab gave local police access to sophisticated forensics technology capable of making mirror copies of data stored on electronic devices.

An amicus brief filed by the Brennan Center for Justice points out that this kind of sophisticated data extraction is not unusual. It is a law enforcement tactic that has become increasingly popular around the country. Since 1999, the FBI has partnered with local law enforcement agencies to establish a network of forensic computer labs in 19 states. When it comes to cell phone data, these laboratories provide local police access to “Cell Phone Investigative Kiosks,” which allow officers to “extract data from a cell phone, put it into a report, and burn the report to a CD or DVD in as little as 30 minutes.” In other words, the police can pull data off your cell phone about your ‘whole life’ in the time it takes you to upload pictures of your vacation to Facebook.

Read More