The nightmare goes like this. In the future, the government will track your every step with miniature GPS devices, or worse, your own phone, turning it into a technological Judas. It will suck up oceans of your most personal data. Its cameras will capture you and its computers will catalog you. Phone companies and others will predict, package and sell your every move. Government eyes will be everywhere. The police will strip you naked at will. And at any moment, a predator drone will park a missile on your nose. Only Summer Glau can protect you.

Is the nightmare here? Maybe. Police departments are now asking phone companies to give them up-to-the-minute location information and other data linked to our cell phones, without a warrant. Phone companies are happy to comply, but not for nothing: They levy "surveillance fees," essentially putting information for sale, including text messages, phone records, and "clones" of phones' contents.

A recent decision, however, shows how resistant America's courts are to this near-term dystopian future. In United States v. Jones, the Supreme Court held that the attachment of a GPS device onto a car to track its movements constitutes a search under the 4th Amendment to the Constitution. The decision was unanimous but the reasoning was fractured; it's already infamous for its Scalia-Alito colloquy comparing GPS devices to "very tiny constables" who, "with incredible fortitude and patience," hitch a stealthy ride on your stagecoach.

In other words, slapping a GPS device under a car's bumper isn't the same as having an officer follow it around, because it's much more effective and far, far easier.

In Jones, the Supreme Court agreed that 4th Amendment search and seizure protections govern the government's use of GPS devices. The judges all agreed that the police should have gotten a valid warrant in that case, and so they agreed that the evidence collected from the GPS device should be thrown out. The judges disagreed, however, on why the government needed a warrant.

The majority opinion, written by Scalia, held that the government's warrantless use of the GPS device on the car was a trespass on personal property. A concurrence, written by Alito, argued that the intrusion was a violation of personal privacy rights. Sotomayor positioned herself as the swing vote, filing her own concurrence, in which she essentially agreed that physical intrusions or privacy intrusions can be "constitutional" searches. She also argued, crucially, that cellphone users have a reasonable expectation of privacy that they not be tracked, and they information gathered about them by third parties not be given up.

What does this mean for covert cellphone tracking? Scalia's view would require a physical trespass before finding that a "search" took place. With cellphone tracking, there isn't an obvious trespass — just a request. The government doesn't plant any item on your property, nor does it need to "seize" anything.

As Alito pointed out, technology is making tracking and surveillance possible without any physical intervention at all. In Alito's view, the longterm monitoring of one's car is a violation of a reasonable expectation of privacy. But when pressed, Alito sounded resigned:

[E]ven if the public does not welcome the diminution of privacy that new technology entails, they may eventually reconcile themselves to this development as inevitable.

Sotomayor wants both our property and privacy interests protected by the Fourth Amendment, and she's not so sure that the "tradeoff" between technology and privacy is worthwhile — or inevitable. But she's more or less alone.

Henry Kissinger famously said that "the illegal we do immediately. The unconstitutional takes a little while longer." Whether our police's new comfort with warrantless phone tracking is legal, illegal, or unconstitutional may well depend on which of these rationales wins the future. In the meantime, keep a close eye on your iPhone. It's probably watching you.

An advocate for the Digital Age, Michael Phillips is an associate at a Wall Street litigation boutique. He has been called a “thick-haired man” by the New York Times.