Have you guys seen this fancy new… cell phone? You can literally take your phone with you and call people from wherever you go. #TBT#ThrowBackThursday

It was 1990 and RadioShack introduced its first transportable cellular phone for $799. 25 years later, struggling to bring customers into its stores over the last few years, the tech store is reportedly preparing to file for bankruptcy protection: http://abcn.ws/1AjMQwF

So this was a pleasant surprise.  Not only because the Roberts Court is notoriously pro law-enforcement, but also because the decision was basically unanimous (Alito filed a partial concurrence).

The Court held first that the warrant requirement applies to cellphones.  They next determined that the “search incident to arrest” exception to the warrant requirement does not apply to cellphones.  They reasoned that none of the circumstances justifying the exception were present in the case of cellphones.  There is no immediate danger to safety or potential for destruction of evidence once the person has been detained.

This was a surprising decision to me.  In United States v. Robinson, SCOTUS held that a pack of cigarettes was subject to the “search incident to arrest” exception, because police may legitimately search containers on the person’s body for weapons and evidence of criminal activity after the person’s been arrested.  I figured SCOTUS would apply this rationale to cellphones as well.  They’d hold that people had a reasonable expectation of privacy in their cellphones, but that the “search incident to arrest” exception applied, thus vitiating the need for a warrant.

I’m glad to see the Court coming to their senses on this issue.  This decision also represents a sea change of the type that was hinted at by Justice Sotomayor in United States v. Jones, when she questioned the idea that people have no reasonable expectation of privacy in information voluntarily disclosed to third parties.  State and federal governments have argued that people have no reasonable expectation of privacy in much of the data on their cellphones because it is voluntarily disclosed to third parties (e.g. GPS data).  Sotomayor wrote:

[I]t may be necessary to reconsider the premise that an individual has no reasonable expectation of privacy in information voluntarily disclosed to third parties.  E.g., Smith, 442 U. S., at 742; United States v. Miller425 U. S. 435443 (1976) . This approach is ill suited to the digital age, in which people reveal a great deal of information about themselves to third parties in the course of carrying out mundane tasks. People disclose the phone numbers that they dial or text to their cellu-lar providers; the URLs that they visit and the e-mail addresses with which they correspond to their Internet service providers; and the books, groceries, and medi-cations they purchase to online retailers. Perhaps, as Justice Alito notes, some people may find the “tradeoff ” of privacy for convenience “worthwhile,” or come to accept this “diminution of privacy” as “inevitable,”post, at 10, and perhaps not. I for one doubt that people would accept without complaint the warrantless disclosure to the Government of a list of every Web site they had visited in the last week, or month, or year. But whatever the societal expectations, they can attain constitutionally protected status only if our Fourth Amendment jurisprudence ceases to treat secrecy as a prerequisite for privacy. I would not assume that all information voluntarily disclosed to some member of the public for a limited purpose is, for that reason alone, disentitled to Fourth Amendment protection.

Today’s case is a good reminder that sometimes, judges plant the seeds of future opinions by engaging in this sort of rumination.  It appears that Sotomayor’s efforts in Jones did not go unnoticed.