In the end, it wasn’t anything David Riley said to police that landed him in prison. It was what his mobile phone said about him.

In 2009, Riley was arrested by San Diego police who suspected him of attempted murder. While in custody, police searched the mobile phone Riley was carrying, and found pictures and texts linking Riley to the crime. Introduced as evidence, those pictures and texts help convict Riley, who is currently serving a sentence of 15 years to life.

How Far Will US Supreme Court Go to Protect Digital Privacy?

Although Riley faded from public view, his case worked its way through the legal system all the way to the U.S. Supreme Court. Last week, all nine justices of the Court agreed that the search of Riley’s phone was unconstitutional in what many privacy advocates are hailing as a landmark ruling. (Not that it helped David Riley much; he remains in prison while his attorneys petition for a retrial.)

How Far Will US Supreme Court Go to Protect Digital Privacy?

declaring mobile phones to be “…a digital record of nearly every aspect…” of users lives was notable for both its unambiguous tone and its potential to reshape how courts see the issue of electronic privacy.

How Far Will US Supreme Court Go to Protect Digital Privacy?

Predicting what cases the Court may hear in the future, much less how they might rule, is a tricky business. Yet it seems clear that other issues of online and digital privacy will only become more frequent as our electronic devices become more personal and pervasive. Reading the Riley decision may provide some important clues as to how this Court sees the issues at play.

“I was very much one of those praising the decision,” says Hanni Fakhoury, an attorney with the digital rights advocacy group the Electronic Frontier Foundation, or EFF.

“I think the Court got it right on the specific issue, and what’s more important, I think the court recognized the 21 century. They recognized that people really do carry all sorts of sensitive and important information on their phones and that triggers privacy protections.”

Fakhoury’s group has a long history of waging legal battles to expand individual’s privacy rights and protections in the U.S. He says the ruling was a rare instance of this Court demonstrating the will to engage with new and emerging technologies and consider the constitutional issues that may be at play.

While some Court observers in the past have decried the justices as who just don’t “get” technology, this opinion, authored by Chief Justice John Roberts, demonstrates a clear understanding of just how much the data on our mobile phones reveals about our private lives.

“Cell phones differ in both a quantitative and a qualitative sense from other objects that might be carried on an arrestee’s person,” Roberts writes. “Notably, modern cell phones have an immense storage capacity.”

Jake Laperruque, a fellow at the Center for Democracy and Technology, is an attorney working on issues of online privacy, surveillance and security. In the past, he says, searches and seizures of a suspect’s personal items were limited foremost by size.

“You couldn’t carry all the contents of every letter you wrote in the palm of your hand, you couldn’t communicate electronically rapidly in the past,” says Laperruque. “Those norms have changed and now we need the law to evolve to protect them. And it seems this Court has embraced that and is willing to protect them.”

The ruling makes clear that smart phones are less like an incriminating letter which a suspect might be carrying, and more like a suspect’s home, which traditionally has been afforded the highest level of privacy protection under the Fourth Amendment.

“The scope of the privacy interests at stake is further complicated by the fact that the data viewed on many modern cell phones may in fact be stored on a remote server,” writes Chief Justice Roberts. “Thus, a search may extend well beyond papers and effects in the physical proximity of an arrestee, a concern that the United States recognizes but cannot definitively foreclose.”

The unanimity of the decision (seven other justices joined in the Roberts ruling, while Associate Justice Samuel Alito concurred with the judgment in a separate ruling) is a clear indication that, at least in this matter, this Court appears sensitive to protecting an individual’s electronic life.

“The Court clearly got it,” said Laperruque. “I think you definitely had a strong understanding in this case from the Court that these new technologies are raising new questions, and that electronic data can be fundamentally different in terms of what it reveals and may be entitled to a fundamentally new type of protection.”

He adds that the ruling is probably the “strongest case” for privacy rights in a long time, and will likely have broad implications.