Page:Riley v. California Syllabus.djvu/3

 Syllabus might warn officers of an impending danger, e.g., that the arrestee's confederates are headed to the scene, such a concern is better addressed through consideration of case-specific exceptions to the warrant requirement, such as exigent circumstances. See, e.g., Warden, Md. Penitentiary v. Hayden, 387 U. S. 294, 298-299. Pp. 10-12.

(ii) The United States and California raise concerns about the destruction of evidence, arguing that, even if the cell phone is physically secure, information on the cell phone remains vulnerable to remote wiping and data encryption. As an initial matter, those broad concerns are distinct from Chimel's focus on a defendant who responds to arrest by trying to conceal or destroy evidence within his reach. The briefing also gives little indication that either problem is prevalent or that the opportunity to perform a search incident to arrest would be an effective solution. And, at least as to remote wiping, law enforcement currently has some technologies of its own for combatting the loss of evidence. Finally, law enforcement's remaining concerns in a particular case might be addressed by responding in a targeted manner to urgent threats of remote wiping, see Missouri v. McNeely, 569 U. S. ____, ____, or by taking action to disable a phone's locking mechanism in order to secure the scene, see Illinois v. McArthur, 531 U. S. 326, 331-333. Pp. 12-15.

(2) A conclusion that inspecting the contents of an arrestee's pockets works no substantial additional intrusion on privacy beyond the arrest itself may make sense as applied to physical items, but more substantial privacy interests are at stake when digital data is involved. Pp. 15-22.

(i) 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. Pp. 17—21.