A bit of encouraging news came today from Washington: The Supreme Court understands smartphones.

Today's unanimous decision in Riley v. California is one of the clearer opinions the court's issued this year. And it's unanimous, thank baby Jesus. (That's more common than you might think, this term.) Police in California had searched a cell phone belonging to Ben Riley, without first getting a warrant. On the phone, they found mentions of his gang membership and involvement in other crimes, information later used in his prosecution.

All of the justices agreed that the police should not have searched the phone without a warrant. They also agreed that the search of a cellphone is simply different in quality than a regular search of personal items upon arrest.

The decision also has broader comforting message: It demonstrates that the Court is at least somewhat interested in understanding how Americans actually live. This type of interest has sometimes been lacking on the court's part, and has in the past led them to wacky conclusions. Like, in Drayton, that law enforcement personnel needn't warn bus passengers of their right to refuse a search.

But here we have a different attitude. Roberts' opinion quite accurately describes, with the help of a few Pew Reports and suchlike, the ways in which cell phones are used by real humans. There is intelligent discussion of how remote wiping might work, and how law enforcement might ward against it. There is acknowledgment that law enforcement has, perhaps, insufficient technological know-how to distinguish between data stored on a cloud and data directly stored on the phone.

That does not mean that Roberts' opinion is wholly devoid of Martian-sounding observations about cell phones, but they're firmly in the "cute" rather than "harmful" category. Witness:

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 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.

This is a supremely important decision. It is a sweeping endorsement of privacy in the digital age, as other commentators are rightly pointing out. It puts a necessary screen around the private lives of Americans in an age where digital surveillance is starting to freak us all out. It rightfully distinguishes a cell phone as carrying more and higher-quality kinds of personal, private information than the extensions of police search power the court has endorsed in the past — like to your car (under limited circumstances), or what's in your pockets.

And I can't endorse this statement of Roberts' enough (and I'm as surprised as you are that I love a Roberts decision this much):

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.

Similarly, it's worrisome that as the CBS legal correspondent Andrew Cohen points out, the Department of Justice has already issued a statement in which it says it intends to search cell phones in ill-defined "exigent circumstances."

One question the Court's empathy for smartphone users' privacy raises: whether or not Roberts, his clerks, or someone else on the court does use an "app to share prayer requests." Or an app for "Republican Party news!" Or, you know, what their browser histories might contain. (Later in the decision Roberts refers to obsessive use of WebMD, for example.)

But please forgive me if I'm also just really curious to know whether Ruth Bader Ginsburg (my favorite) uses Snapchat. And what Instagram filters she likes. And also whether she's really great at texting.

Which probably just goes to show you: people's phones really do need some kind of protection, even from the benevolently interested.

[Image via Getty.]