"Finally, there is an element of pervasiveness that characterizes cell phones but not physical records. Prior to the digital age, people did not carry a cache of sensitive personal information with them as they went about their day. Now it is the person who is not carrying a cell phone, with all that it contains, who is the exception," the ruling says. "A decade ago police officers searching an arrestee might have occasionally stumbled across a highly personal item such as a diary. But those discoveries were likely to be few and far between. Today, by contrast, it is no exaggeration to say that many of the more than 90% of American adults who own a cell phone keep on their person a digital record of nearly every aspect of their lives -- from the mundane to the intimate. Allowing the police to scrutinize such records on a routine basis is quite different from allowing them to search a personal item or two in the occasional case."
The court acknowledged, however, that the ruling will have an effect on the ability of police to combat crime, but privacy must prevail.
"We cannot deny that our decision today will have an impact on the ability of law enforcement to combat crime," the ruling says. "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."