This editorial appeared in the Chicago Tribune.
IN THE modern world, people have largely adjusted to the realization that they can't hide. Someone -- Google, Apple, Verizon, any number of app makers -- knows an enormous amount about them, including where they are almost all the time.
But it's one thing for your fitness watch to track your location continuously and another for the police to do it. Once your every movement is laid bare to law enforcement agencies, the perpetual surveillance becomes much more threatening.
The Supreme Court, fortunately, is waking up to the unprecedented dangers to privacy posed by the technology of the present and future. Last week the justices ruled that police must obtain a search warrant to get data from cellphone towers that can be used to track someone's whereabouts. In doing so, the court acknowledged that some of its previous rulings were an unsatisfactory guide to the issues presented in this new environment.
In the case at hand, police got data for Timothy Carpenter, who was suspected of planning and assisting in armed robberies of Radio Shack and T-Mobile stores in the Detroit area. The records documented his location an average of 101 times a day over the course of several months -- placing him close to some of the crimes. Convicted on multiple counts, he was sentenced to 116 years in prison.
But by a 5-4 vote, the court overturned the convictions on the ground that the police "invaded Carpenter's reasonable expectation of privacy."
The government argued that under the court's precedents, data compiled about a customer by a bank, a phone company, or an insurance provider is not private because the individual has already exposed it to the view of a "third party." But Chief Justice John Roberts saw the absurdity of applying the doctrine in these circumstances.
"In the first place, cell phones and the services they provide are ‘such a pervasive and insistent part of daily life' that carrying one is indispensable to participating in modern society," he wrote for the majority. "In no meaningful sense does the user voluntarily ‘assume the risk' of turning over a comprehensive dossier of his physical movements."
Not only can the government now achieve "near perfect surveillance, as if it had attached an ankle monitor to the phone's user," it can "travel back in time to retrace a person's whereabouts," the court noted. This "tireless and absolute surveillance" is vastly different from what could be done in the past.
This case will not be the last in which the court has to decide how to adapt the guarantees in the Bill of Rights to the unforeseen challenges posed by advanced technology. But the justices have laid down a needed marker.