June 25, 2014 was historic for mobile phone users in the U.S. The U.S. Supreme Court ruled on the case Riley vs. California, that police may not search the “contents” of a cell phone of an arrested suspect without a search warrant. The ruling points out that a cell phone isn’t like a cigarette pack or a piece of paper found in an arrestee’s pocket. Nor is it akin to a glove compartment within easy reach of the driver of a car who has been arrested. The syllabus (headnote) of the decision states:

“Cell phones differ in both a quantitative and a qualitative sense from other objects that might be carried on an arrestee’s person. Notably, modern cell phones have an immense storage capacity. Before cell phones, a search of a person was limited by physical realities and generally constituted only a narrow intrusion on privacy. But cell phones can store millions of pages of text, thousands of pictures, or hundreds of videos. This has several interrelated privacy consequences. First, a cell phone collects in one place many distinct types of information that reveal much more in combination than any isolated record. Second, the phone’s capacity allows even just one type of information to convey far more than previously possible. Third, data on the phone can date back for years. In addition, an element of pervasiveness characterizes cell phones but not physical records. A decade ago officers might have occasionally stumbled across a highly personal item such as a diary, but today many of the more than 90% of American adults who own cell phones keep on their person a digital record of nearly every aspect of their lives.

The scope of the privacy interests at stake is further complicated by the fact that the data viewed on many modern cell phones may in fact be stored on a remote server. Thus, a search may extend well beyond papers and effects in the physical proximity of an arrestee, a concern that the United States recognizes but cannot definitively foreclose.”

~ Supreme Court Syllabus: Riley v California

My favorite comment on the ruling came in the Opinion from Chief Justice John Roberts:

“Modern cell phones are not just another technological convenience. With all they contain and all they may reveal, they hold for many Americans ‘the privacies of life’… The fact that technology now allows an individual to carry such information in his hand does not make the information any less worthy of the protection for which the Founders fought. Our answer to the question of what police must do before searching a cell phone seized incident to an arrest is accordingly simple—get a warrant.”

The ruling is at:
supremecourt.gov/opinions/13pdf/13-132_8l9c.pdf

The decision does not address the issue of whether the NSA or the FBI may search the contents of our cell phones, or the data captured, or phone calls made, without a warrant. The ruling also doesn’t define search as requiring human observation vs. an automated scan, trolling for suspicious entries or utterances. But it does address the ability of U.S. law enforcement to perform warrantless searches on cellphone data that is housed in a cloud, rather than on the phone itself. Essentially, both searches require a warrant.

It’s a huge step in keeping the U.S. from sliding further down the slippery slope of invading our privacy.