Page:Riley v. California Opinion.djvu/20

 Opinion of the Court feature on many smart phones and can reconstruct someone's specific movements down to the minute, not only around town but also within a particular building. See United States v. Jones, 565 U. S. ____, ____ (2012) (SOTOMAYOR, J., concurring) (slip op., at 3) ("GPS monitoring generates 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."). Mobile application software on a cell phone, or "apps," offer a range of tools for managing detailed information about all aspects of a person's life. There are apps for Democratic Party news and Republican Party news; apps for alcohol, drug, and gambling addictions; apps for sharing prayer requests; apps for tracking pregnancy symptoms; apps for planning your budget; apps for every conceivable hobby or pastime; apps for improving your romantic life. There are popular apps for buying or selling just about anything, and the records of such transactions may be accessible on the phone indefinitely. There are over a million apps available in each of the two major app stores; the phrase "there's an app for that" is now part of the popular lexicon. The average smart phone user has installed 33 apps, which together can form a revealing montage of the user's life. See Brief for Electronic Privacy Information Center as Amicus Curiae in No. 13-132, p. 9.

In 1926, Learned Hand observed (in an opinion later quoted in Chimel) that it is "a totally different thing to search a man's pockets and use against him what they contain, from ransacking his house for everything which may incriminate him." United States v. Kirschenblatt, 16 F. 2d 202, 203 (CA2). If his pockets contain a cell phone, however, that is no longer true. Indeed, a cell phone search would typically expose to the government far more than the most exhaustive search of a house: A phone not only contains in digital form many sensitive records