Opinion of the Court
ing matters means that law enforcement officers may well not be able to turn their attention to a cell phone right away. See Tr. of Oral Arg. in No. 13-132, at 50; see also Brief for United States as Amicus Curiae in No. 13-132, at 19. Cell phone data would be vulnerable to remote wiping from the time an individual anticipates arrest to the time any eventual search of the phone is completed, which might be at the station house hours later. Likewise, an officer who seizes a phone in an unlocked state might not be able to begin his search in the short time remaining before the phone locks and data becomes encrypted.
In any event, as to remote wiping, law enforcement is not without specific means to address the threat. Remote wiping can be fully prevented by disconnecting a phone from the network. There are at least two simple ways to do this: First, law enforcement officers can turn the phone off or remove its battery. Second, if they are concerned about encryption or other potential problems, they can leave a phone powered on and place it in an enclosure that isolates the phone from radio waves. See Ayers 30-31. Such devices are commonly called "Faraday bags," after the English scientist Michael Faraday. They are essentially sandwich bags made of aluminum foil: cheap, light-weight, and easy to use. See Brief for Criminal Law Professors as Amici Curiae 9. They may not be a complete answer to the problem, see Ayers 32, but at least for now they provide a reasonable response. In fact, a number of law enforcement agencies around the country already encourage the use of Faraday bags. See, e.g., Dept. of Justice, National Institute of Justice, Electronic Crime Scene Investigation: A Guide for First Responders 14, 32 (2d ed. Apr. 2008); Brief for Criminal Law Professors as Amici Curiae 4-6.
To the extent that law enforcement still has specific concerns about the potential loss of evidence in a particular case, there remain more targeted ways to address
