GPS detectors, jammers & spoofers

On Friday, I spoke to a group of lawyers about various issues in criminal law and technology. One of the issues we talked about is the police's use of Global Positioning System (GPS) devices to track people’s movements. (GPS devices are used by private parties, as well, but my focus here is on criminal matters, so I’m only going to deal with the government’s use of them.)

This is really a follow-up to a post I did a while back, on Anti-GPS technology. Since I found the technology here is more complex that I realized, I thought I'd do a follow-up on the issue.
Under current law in the U.S., the Fourth Amendment’s prohibition on unreasonable searches and seizures are not implicated when the government installs a GPS device on someone’s vehicle and uses it to track their movements in public places. Courts have held that installing the device is not a seizure of your vehicle because it in no way interferes with your operation or use of the vehicle; you don’t even know the device is there (which is the point, after all). At least one state court has held that police do need a warrant, but that decision was made under state law and I’m focusing on the Fourth Amendment, because it is the default general national standard.

They have also cited a 1983 U.S. Supreme Court decision upholding the use of “beepers” to help police follow suspects in their vehicles for the proposition that it is not a search for the government to use a GPS device to track your movements in public places. (Courts say it is a search if police use GPS to track you into a private place, like your garage.) They have reached this conclusion even though a GPS device, unlike the beeper at issue in the Supreme Court case, substitutes for a police officer; the device tracks your movements without a police officer’s having to be assigned to follow you around. At least one state court has said that makes a difference under state law, because GPS lets police conduct surveillance on a larger scale than they could if they had to have officers follow people around; and the Seventh Circuit Court of Appeals noted that this might be a problem in the future, if police really begin to use GPS devices on a wide scale.

But, as of now, police do not have to get a search warrant to install and/or monitor a GPS device. Both activities are completely outside the Fourth Amendment, and that means police can install and monitor the device without your knowing anything about it (which, as I noted above, is the whole point). The basic practice when they have to get a warrant to do something is that they serve the warrant on you, then conduct a search of your home or other property, and then leave you with an inventory of what you took. That way, you know they were there, why they were there and what they took.

In the course of talking about this with the bar association on Friday, I suggested this might create a market for GPS detectors, and we talked about that a bit. One of the attorneys there, who has a good technical background, said there’s no way to use a detector to discover a passive GPS tracking device (GPS logger) that simply stores up information about your movements, but that a detector could be effective for an active device (GPS tracker) that transmits information periodically. So we talked about that a bit, and I joked as to how there could become a real market for these things.

I decided to see if GPS detectors are on the market and, yes, there are some. There are also GPS jamming devices and spoofers. I’ll talk a bit about each type of device, and then we’ll consider the legality of using any or all of them devices, now and in the future.

According to one site, it is possible to detect a GPS tracking device that transmits information by using a radio frequency detector/scanner. The problem, according to this site, is that the RF detector/scanner will only detect the transmissions of the GPS device when the device is actually transmitting. This site also notes that GPS devices use different technologies, which can also cause complications in detecting them. Another site follows up on that, explaining that some trackers do transmit a constant signal, which makes them easier to detect, and that the same is true of GPS devices that use cell phone connections. The site says ultimately the best way to find a GPS device is to use a combination of detection and “finger-tip searching.”

We, though, are interested in the use of technology to find GPS tracking devices, so we’ll stay with that. Before we consider the legality of using GPS detectors, I want to consider the second logical approach to dealing with a GPS tracking device: GPS jamming.

I found a website that advertises at least two different GPS jamming devices. Both plug into your vehicle’s cigarette lighter, and both jam a GPS device’s ability to collect and/or transmit location information. I also discovered that it is possible to spoof the signals sent to a GPS device, so the device thinks it is in Place A when it’s really in Place B.

As far as I can tell, there are no laws in the U.S. that criminalize the use of GPS detectors, jammers or spoofers. Since I can see objections being raised to the use of these devices if and when they become more popular, I want to speculate a bit as to whether the use of any of these devices could legitimately be outlawed.

The obvious source of analogy here is radar detectors. Like GPS detectors, jammers and spoofers, radar detectors allow those who use them to evade police surveillance technology.

A very few US states outlaw radar detectors. Virginia, for example, has a statute that makes it unlawful “to operate a motor vehicle on the highways of the Commonwealth when such vehicle is equipped with any device . . . to detect or purposefully interfere with . . . the measurement capabilities of any radar, laser, or other device . . . employed by law-enforcement personnel to measure the speed of motor vehicles on the highways”. Virginia Code section 46.2-1079(A).

In 1987, a bill was introduced in Congress that would have made it a federal crime to manufacture, sell or possess a radar detector, but the bill languished and finally disappeared. See H.R. 2102, 100th Congress, 1st Session (1987). There was apparently little support for such a measure because, as one author notes, “the nationwide criminalization of a segment of the electronics industry and its consumers is arguably unjustifiable and implicates questions of federalism. Proponents of federalism allege that the issue is best left to state legislatures.” Nikolaus Schandlbauer, Busting the “Fuzzbuster:” Rethinking Bans on Radar Detectors, 94 Dickinson Law Review 783, 789 (1990).

There seems to be no reason why states cannot outlaw radar detectors. A federal court of appeals upheld the constitutionality of the Virginia ban, agreeing with the district court that it “furthers a significant state interest in the health or safety of Virginia’s motorists”. Bryant Radio Supply, Inc. v. Slane, 507 F. Supp. 1325 (District Court of Virginia 1981), affirmed 669 F.2d 921 (Fourth Circuit Court of Appeals 1982). Notwithstanding that, most states have chosen not to outlaw them, presumably because they do not feel the evasion of law at issue here warrants such a punitive measure.

What about GPS detectors, jammers and spoofers? Can they legitimately be outlawed? Should they be outlawed?

In answering those questions, there may be some reason to differentiate between (a) detectors and jammers and (b) spoofers. From my brief research online, it seems that spoofers can be used by thieves who want to hijack cargo being moved by trucks; the thieves can apparently use the spoofed GPS signals to disguise the fact that a truck is deviating from its authorized route, a deviation which is leading up to the theft of its cargo. So, spoofing can be used to commit distinct, freestanding crimes as well as to frustrate law enforcement surveillance. While the same might be true of the other two types of GPS countermeasures, I am going to assume they only frustrate surveillance, and so am going to treat them differently.

As to spoofers, the answers to the questions I posed above are “yes,” in both instances. If spoofers can be used to set up cargo thefts and other crimes, then they are analogous to burglar’s tools. As I have explained before, many states outlaw the mere possession of burglar’s tools (which are usually defined as items that, in isolation or when collected together, clearly have no purpose other than illegal break-ins). The justification for these statutes is that they outlaw a type of attempted crime; in other words, there is no reason to possess burglar’s tools except to use them in a burglary. Spoofers are, I think more ambiguous: I am not sure they have any legitimate purpose, but they can be used either to (a) frustrate law enforcement surveillance or (b) to facilitate cargo thefts and maybe other types of crimes, as well. To the extent they fall into category (a), they should be encompassed by my analysis of the legality of outlawing jammers and detectors, which we’ll get to in a moment. To the extent they fall into category (b), they can be outlawed if they are truly analogous to burglar’s tools, i.e., if they have no independent legitimate use.

As to detectors and jammers, we need to analyze each of them separately. It seems to me that GPS detectors are very much analogous to radar detectors, in that they do not interfere with the functioning of law enforcement surveillance technology; they simply alert the target of the surveillance so that he or she can take appropriate measures to frustrate the surveillance. One could, therefore, argue that there is no more reason to outlaw GPS detectors than there is to outlaw radar detectors. The problem I see with this argument is that radar detectors are used only to detect a very low level of criminal activity, but GPS devices are usually used in investigating more serious crimes. That could make a real difference in how states answer the two questions I posed above. Because these detectors frustrate surveillance in investigations targeting more serious crimes, they could be seen as an effort to obstruct justice. (The same is true of radar detectors, but here the frustration is at a very low level, given the minor criminal activity at issue.) Indeed, one can argue that this is their whole purpose. If you accept that view of GPS detectors, the answers to the two questions I posed above are, again, “yes.”

What about GPS jammers? The analysis I went through in the paragraph above seems to apply to them, too. And there is an aggravating factor here. According to what I read on several websites, jamming GPS signals can create a safety hazard for ground vehicles and/or for aircraft. If that is true, then the use of these devices creates a new, distinct hazard to public safety, and the creation of such a hazard is a matter the criminal law can legitimately address. I suspect, then, that if GPS jammers begin to be used with any frequency, we will see efforts to outlaw their use at the state and/or federal level. I understand that their use is already illegal in European Union countries.