What was perhaps most revealing about the Court's thinking was a description of how the apps that a person could have on a phone can disclose about them. He mentioned apps for everything from political activity, addiction treatment, pregnancy tracking and even for improving your romantic life. Roberts also noted the added complexity of cloud-based storage, and how that could be used and followed by the government.
Roberts focused specific criticism at a government proposal that law enforcement agencies develop protocols to address the concerns of cloud computing
. "Probably a good idea," he wrote, but then added searingly, "but the Founders did not fight a revolution to gain the right to government agency protocols."
Roberts wrote that the privacy interests that would arise from warrantless searches of evidence in the cloud that are not in the proximity of an arrestee would dwarf the concerns that have arisen in previous cases.
Following the decision, a number of law enforcement organizations have criticized it claiming that requiring a warrant to search the contents of a cell phone would hamper police investigations and endanger police.
However, Justice Roberts had already formed an answer for that criticism. Police, he said, had already shown that they could email a request for a warrant to a judge, have the judge sign it on his iPad and return it to the police in 15 minutes.
A number of industry and privacy groups hailed the Court's decision. "This is a crucial ruling that assures individuals their photos, letters, travel records and other documents revealing their lives have the same protection on their mobile phone as information stored in a desk at home," said Ed Black, president and CEO of the Computer and Communications Industry Association.
"As technology advances and people rely more on their phones and less on paper records it is critical that 4th amendment protections against search and seizure keep up with that. We hope the next step is for Congress to pass pending legislation to ensure this warrant protection for other online communications."
The Court acknowledged that their decision will cause problems. "We cannot deny that our decision today will have an impact on the ability of law enforcement to combat crime," Roberts wrote in the Court's decision. "Cell phones have become important tools in facilitating coordination and communication among members of criminal enterprises, and can provide valuable incriminating information about dangerous criminals. Privacy comes at a cost."
What's important in this decision is that the court carefully weighed the vast potential privacy impact if cell phones are fair game for warrantless search. The court also made note of a variety of related information that should be protected, notably information on the position of a phone, and the other data, specifically forms of metadata. Is it safe to assume that this decision could be a precursor to decisions on other methods of capturing data from phones, perhaps by the National Security Agency?