Last month the U.S. Supreme Court ruled (in U.S. v. Jones) that the warrantless tracking of U.S. citizens via GPS devices is illegal. Following the decision, the FBI and other law enforcement agencies rushed to turn off approximately 3,000 trackers that were then in use in the field.

But while “about” 3,000 trackers were, at least temporarily, turned off (only about 10% of them permanently, according to NPR), nobody really seems to know exactly how many devices are out there. Forbes staff writer Kashmir Hill writes:

So what are the actual numbers here? According to an FBI spokesperson, the Bureau doesn’t exactly know either. A spokesman says the 3,000 number referred to the “universe of trackers” — and may reflect the total used over a given year, or the total in use at any one time, or someone’s dartboard score. “It’s an oversimplification,” said an FBI spokesperson.

…

“The problem is there’s no national database,” says Scott Burns, executive director of the National District Attorneys Association. “I can say, anecdotally, that across the country, prosecutors now have to meet with law enforcement to prepare affidavits and warrants when they want to use a tracker.”

The FBI complains that the new restriction makes it tough on law enforcement to do its job efficiently. “We have a number of people in the United States whom we could not indict, there is not probable cause to indict them or to arrest them who present a threat of terrorism,” said FBI Director Robert Mueller in a House Appropriations Committee hearing earlier this month. But that’s kind of the point of the Fourth Amendment, which guarantees that the balance of power between citizens and law enforcement will not be tipped too unfairly in the government’s favor.

So now a lot of agencies are having to go old-school on suspects, says NPR, using teams of up to eight agents to tail and photograph people whom they suspect of a crime, but for whom they have found no probable cause or sufficient evidence to obtain a warrant.

The jury’s still out (kind of literally — see what I did there?) on other forms of digital tracking. Your location can already be tracked via your cell or smart phone, even if you’re not anybody’s foursquare mayor. And most new cars being rolled out today are equipped with some sort of built-in GPS device. Forbes’s Hill reports that two recent cases have met with contradicting rulings over the legality of government’s tracking you on your own devices. So the precedent’s still up in the air. Just as law enforcement agents have been advised to play it conservative and get a warrant before electronically tracking citizens, I’m also going to bet that until a single ruling becomes precedent, or a case heads to the Supreme Court, agencies are probably going to use your devices if that’s their easiest course of option. Better to ask forgiveness than permission, right?

So in the meantime, if you care about your privacy, what can you do to make sure you’re not being tracked? Well, I’d tell you to pay for everything in cash, use disposable cell phones, and keep your head down in the presence of security cameras.

But that’d probably be cause enough to get you followed, if you weren’t already.

[Forbes, NPR, Photo Cred: IFixIt]