Frankly, I’m amazed the GPS gave them useful information. Mine just yells Turn Left! Keep Right! Recalculating! and orders me to turn into a lake. (Daniel Acker/BLOOMBERG)

But in the debate about the constitutionality of tracking the movements of suspected criminals with GPS but without a warrant, one thing struck me: all the references to “1984.”

Like the Constitution, “1984” has stood the test of time because of its universally acclaimed ability to imagine and account for the future. The omnipresent Big Brother. Citizens being stared at by telescreens.

But the actual future is outpacing our ability to imagine the future.

These days, Orwellian, “1984”-ish scenarios would come as a positive relief. Sure, I want my face eaten by rats as much as the next guy, which is to say, not at all, unless the next guy has some sort of weird fetish. But now we welcome the cameras in. We type our personal data into the telescreens. We pump the Tubes full of our innermost thoughts, hopes, dreams, and most embarrassing videos.

Imagining the future is always difficult. By all accounts, we should be surrounded by zeppelins right now. Where are our robot servants?

What made the decision in this case comparatively simple was the fact that the police had put the tracker on the suspect’s car without a warrant or his permission. That’s something Orwell could have pictured.

But more worrisome is the scenario he didn’t.

In Justice Scalia’s majority opinion, he wrote, “The government physically occupied private property for the purpose of obtaining information. We have no doubt that such a physical intrusion would have been considered a ‘search’ within the meaning of the Fourth Amendment when it was adopted.”

Scalia gives one the perpetual sense that whenever he goes outside he is startled by all the metal birds and horseless carriages milling about. “The Founders did not mention these,” he mutters to himself, darting indoors and tugging on his homespun britches. He opposes things for reasons like, “once, Thomas Jefferson was frightened by a horse, and he told me last night that this is like that.”

But it's cases like these that suggest some of the challenges for strict constructionists. GPS is the sort of thing of which the Founders had no conception. Heck, cars are the sort of thing of which the Founders had no conception. Even Maxwell’s Demon might be pushing it.

The Founders were wise enough to foresee that there would be all sorts of things they did not foresee. The decision was unanimous. But in the concurrence, Justice Alito noted that physical intrusion is no longer necessary to surveillance. Besides, “it is almost impossible to think of late-18th-century situations that are analogous to what took place in this case. (Is it possible to imagine a case in which a constable secreted himself somewhere in a coach and remained there for a period of time in order to monitor the movements of the coach’s owner?... Something like this might have occurred in 1791, but this would have required either a gigantic coach, a very tiny constable, or both.)”

Our ability to envision the future is being put to the test.

The dominant characteristic of Orwell’s world is the sense that you are being watched. Of course we are. We want to be.

In her concurring opinion, Justice Sotomayor said something quite interesting. “It may be necessary," she wrote, "to reconsider the premise that an individual has no reasonable expectation of privacy in information voluntarily disclosed to third parties. This approach is ill-suited to the digital age, in which people reveal a great deal of information about themselves to third parties in the course of carrying out mundane tasks.”

“I for one doubt that people would accept without complaint the warrantless disclosure to the government of a list of every Web site they had visited in the last week, or month, or year.”

She's got our number.

Talk about unreasonable searches. We make dozens of unreasonable searches every day. Googling comes more naturally than thought. What’s the name of that guy in that movie? When is Canadian Thanksgiving? Where can I hide the body? Kidding, Google, I was kidding. Do we have some expectation of privacy? If I had a dime for every time I’d looked up something incriminating on the Internet, I could retire right now.

It’s not Big Brother and the tiny constables we should be worried about. It’s the person on the other side of the screen.

What would the Founders have said? You can imagine Ben Franklin having a truly jaw-dropping search history, Alexander Hamilton with a vibrant Twitter presence, Aaran Burr forwarding you strange attachments that turned out to contain viruses, John and Abigail Adams leaving extended comments on each other’s Facebook walls. And GPS would have made things much easier for Lewis and Clark. Using the Internet and its myriad gifts of information, directions, and connections can be a process as intimate as thought. But unlike thought, it leaves traces everywhere. What are we going to do with those? Even for GPS, the Court only hinted at an answer.