Appeals Court Rules Against Long Term Warrantless GPS Tracking Of Suspect; Sets Up Inevitable Supreme Court Case

from the ah-that-4th-amendment dept

For years, we’ve been discussing the “Pandora’s box” of privacy and 4th Amendment questions about law enforcement using secretly installed GPS devices to track suspects. For more than five years, we’ve been wondering when the Supreme Court would finally weigh in on the issue. There have been plenty of cases on this topic so far, with various federal courts ruling that it’s perfectly legal and various state courts generally ruling in the opposite manner. Well, today the appeals court for the DC Circuit ruled that a long-term use of GPS to track someone without a warrant violates the 4th Amendment. While other courts found that GPS was really no different from just following someone in public, this court found otherwise:

“It is one thing for a passerby to observe or even to follow someone during a single journey as he goes to the market or returns home from work. It is another thing entirely for that stranger to pick up the scent again the next day and the day after that, week in and week out, dogging his prey until he has identified all the places, people, amusements, and chores that make up that person’s hitherto private routine.”

Specifically, the court found that the whole of the activity may add up to more than just the sum of the parts. While this makes sense, there are a lot of questions as to whether it goes way beyond what the law allows. Eugene Volokh Orin Kerr notes a key problem:

Much of the problem is knowing when the line is crossed when a bunch of non-searches become a search. The Supreme Court has stressed the need for clear rules that tell the police what they can and cannot do. But how do the police know when a mosaic has been created such that the sum of law enforcement techniques, when aggregated, amount to a search? Are they supposed to carry around a D.H. Ginsburg Aggregatormeter that tells them when it’s time to get a warrant? Take the case of Maynard. One-month of surveillance is too long, the court says. But how about 2 weeks? 1 week? 1 day? 1 hour? I have no idea.

Even stranger, the mosaic theory has the bizarre consequence of creating retroactive unconstitutionality. The Maynard opinion indicates that it would have been okay to monitor Jones for a short time. Let’s say that would allow monitoring for a few trips over the course of one day. At the end of that one day, the first day of monitoring would be constitutional. If the prosecution wanted to admit that evidence, it would be fine. But by continuing to monitor the GPS device for more time, that first day of monitoring eventually and retroactively becomes unconstitutional. It becomes part of the mosaic, and the key point of Maynard is that the entire mosaic is considered one entity.

I have to admit, I see both sides of this argument. The full on, warrantless GPS tracking certainly does seem to go beyond what’s reasonable. But the vague standard could create some problems as well (even if I generally like the idea of looking at the whole of the activity, rather than trying to focus in on the individual pieces). It seems like the good way out of this would be for Congress to protect privacy by requiring a warrant for such tracking, but there’s little chance of that happening. Instead, what’s likely to happen is that the Supreme Court will be forced to weigh in on this eventually, and my (very premature) guess is that they’ll side with law enforcement.

Filed Under: , ,

Rate this comment as insightful
Rate this comment as funny
You have rated this comment as insightful
You have rated this comment as funny
Flag this comment as abusive/trolling/spam
You have flagged this comment
The first word has already been claimed
The last word has already been claimed
Insightful Lightbulb icon Funny Laughing icon Abusive/trolling/spam Flag icon Insightful badge Lightbulb icon Funny badge Laughing icon Comments icon

Comments on “Appeals Court Rules Against Long Term Warrantless GPS Tracking Of Suspect; Sets Up Inevitable Supreme Court Case”

Subscribe: RSS Leave a comment
direwolff (profile) says:

Aggregation needs its own review

The issue of how things change when aggregated is certainly on display in this matter, but it’s also on display in other privacy centric issues. Daniel Sokolove’s paper “‘I’ve Got Nothing to Hide’ and Other Misunderstandings of Privacy” (, certainly draws this out as one of the problems in his taxonomy of privacy.

In an article penned by Kashmir Hill titled “Confessions of an Online Stalker” (, we see just how murky the waters get as one crosses the line fm finding out a couple of items about a person, to creating a dosier on them outlining their life and background and all sorts of things they would never want compiled in one place.

So aggregation as a tenet of privacy needs to be more directly discussed and explored to resolve the sorts of issues raised by this ruling. As the court appears to have suggested, it’s the fact that the GPS surveillance was constant which made the FBI’s actions an issue. In other words, the aggregation of many consecutive moments. This is equally troublesome when companies or governments begin aggregating info about us fm various databases where none of the intended uses had ever been for their data to be used in this manner.

Thorny issues indeed and I’m not sure that our elected officials or courts are prepared to handle these nuances, or that even if they try, policing these will be possible.

N2iT (profile) says:

Re: Aggregation needs its own review

The NSA and CIA and other law enforcement agencies have rules to where they can apply tracking devices on a person as in their clothes and what not and since the court agreed that even though the jeep was owned by his girlfriend that he was the principle driver wouldn’t that the same as tracking you personally

slacker525600 (profile) says:

just wondering

how do they justify using gps to track you on private property? I mean, the justification that the gps tracker is the same as following you around makes sense while you are in public, but say you go onto a large private property where they would be unable to follow you without a warrant, I cannot imagine that they deactivate the gps.

I also dont know what the legality is for satellite surveillance. seems like an unreasonable search to me, but I suppose its just a picture taken from a pretty high vantage point

DCX2 says:


They only had one piece of evidence in this case, which was the GPS data. When the substance of your case lies on some evidence, you should really make sure you err on the side of safety and make sure the evidence was collected legally. They wouldn’t be GPS tracking someone without a good reason (…hopefully…), so it shouldn’t be hard to get a judge to sign off on it, right?

Now, I’m really intrigued with the concept of limiting the ability of actors to aggregate information. direwolff is right, going to such lengths is much like creating a dossier, and not much different from stalking. It is definitely an invasion of privacy.

The problem is…this is already happening on a massively widespread scale. Everything we do is analyzed, either by the government or by advertisers or by Google. Fortunately, they don’t generally have the power to arrest you.

vrob (profile) says:

Re: Eh...

“They wouldn’t be GPS tracking someone without a good reason (…hopefully…), so it shouldn’t be hard to get a judge to sign off on it, right?”

That should be true, and it generally is true. In the law, a “good reason” for a warrant is called “probable cause.” If probable cause exists it is usually not hard to get a judge to sign off on a warrant.

There are also circumstances in which a warrant is not required. However, these “exigent circumstances” generally require some immediate threat to personal/public safety, or loss of evidence, etc.

This reminds me of cases in which new technologies are employed for a “search” and the question raised is whether it is a simple enhancement of the senses (binoculars); or something extra and unusual (infra-red glasses that read heat signatures). My understanding is that a simple enhancement is OK, but new technology that goes beyond our natural senses is more complicated. GPS tracking devices seem to fit into the latter category.

DCX2 says:

Re: Re: Eh...

Yeah…exigent circumstances. That’s perfect. If you’re taking your time to aggregate GPS data, there is clearly no exigent circumstance.

But if you see a crime go down, and you want to follow the perp back to his place, and he can’t know you’re tailing him. You can’t get to a judge for the warrant in time. So you throw the GPS tracker on. Once the perp gets to the destination, the force is immediately busted out…no aggregation.

Anonymous Coward says:

Re: Re: Re: Eh...

I think we agree, but you sound upset for some reason that is unclear to me. This case is more about a person’s legitimate “expectation of privacy” and whether using technology to enhance the process of gathering information violates the Fourth Amendment than it is about aggregation. My point about “exigent circumstances” was intended simply to point out why it might be OK to use GPS tracking for a day but not a month.

Carolyn R Nardella says:

Just got fired

I just got fired after over 3 years and I don’t believe the gps. My record indicate that I was traveling 50 mph.Can you please help me. You know so much about this. It was the speed gps that caught me and there is no way that I would do that rate of speed. Thanks a bunch.
Carolyn R Nardella
5 L Meadowview Est
Clinton, CT 06413

Thank you in advance.

btr1701 (profile) says:


The actual fallacy of the court’s argument is not pointed out in the article.

Even if you agree that the sum of the various tracks is qualitatively different than each taken separately, that is still not the reason for the finding that it is illegal. The court didn’t say that tracking a suspect by *any means* over the course of weeks without a warrant is unconstitutional. It said that tracking him using GPS over the course of weeks without a warrant is unconstitutional. That would imply that it would still be perfectly legal to do the surveillance the old-fashioned way and follow a suspect around (without a warrant) for as long as they want, documenting much of the same information (if not more and in greater detail) as the GPS would provide. The only difference between the two is that it is much more expensive for the government and more likely to tip off the suspect that he’s being surveilled if done without GPS.

The same investigation undertaken without electronic aid is apparently seen differently under the law even though they uncover the same information for law enforcement.

Since it could be easily argued that personally following a suspect around would actually uncover more and better quality information, and that at a minimum the vehicle location info would be the same, the court is essentially saying that it is not the information you are acquiring, but the way you are acquiring it which makes it illegal.

The only possible caveat to this that I can see is that to enable the electronic tracking, a trespass of some sort has to take place to attach the monitor to the person’s property. While still minimal, it is an actual difference between the two forms of surveillance. Another difference would be if the suspect was able to go to places where the law enforcement agency would not have jurisdiction or could not enter without a warrant and the information provided from the GPS gave them information that could not have been obtained utilizing personal surveillance.

However those do not seem to be at issue here.

Anonymous Coward says:

Re: GPS Law

The problem here is both the means by which the information was gathered and the fact that there was not a valid warrant. We should be happy that a person’s “reasonable expectation of privacy” is being upheld here. The Warren Court expanded our rights under the Fourth Amendment, but they are not written in stone. Cherish your rights.

nasch (profile) says:

Re: GPS Law

The only possible caveat to this that I can see is that to enable the electronic tracking, a trespass of some sort has to take place to attach the monitor to the person’s property. While still minimal, it is an actual difference between the two forms of surveillance.

I don’t know if the law says so, but I agree with you. I don’t mind police following someone around in public without a warrant if it’s within the reasonable scope of an investigation, but when they attach something to someone’s property, there had better be some real oversight.

Anonymous Coward says:

To me, it seems the court can draw a line between GPS surveilance and phone surveilance – the surveilance must be within the scope of the investigation/warrant. You can’t listen in on a phone conversation about groceries and picking up the kids from school if the investigation is about drug dealing for instance. I can see the court taking a similar approach to GPS surveilance. However, the issue here would be what movement would fall within the scope of the investigation – would it have to be continuously on to create a daily pattern and follow up on the outliers?

legend says:

Warrantless SPYING

To the Judges.

Consent of the governed DOES NOT INCLUDE affording the right to track them. Assuming that all porposes that tracking are used for are Noble is to say that illegal activity does not exist within law enforcement circles, and that Santa truly does come in December. Take, for example, the brothers in blue in eastern North Carolina, who enter target’s homes and steal money, coins, and personal effects while utilizing the cameras that Brother Walter B. Jones and company situated across the extant of their target’s travel routes and commercial concerns. If the government can know your location in localles other than your home, other brothers can then be free to enter your home and effect silent retaliation against you by damaging and stealing all within your home. And if you think the brothers of Freemasonry are beyond retaliating against their enemies, consider that Kennedy was killed for speaking against the Freemasons. Now it is apparent Freemasons across the court systems are in league, just as the East German Stasi Communists were before they were swept away by time and the governed, whom they sought to repress. Poindexter, freemason as well, must be chuckling somewhere at America’s gullibility. People actually believe that total surveillance and cameras everywhere are good. They will until THEIR HOMES are rifled by thugs, brothers.

Anonymous Coward says:

Aggregatormeter specifications

> Are they supposed to carry around a D.H. Ginsburg Aggregatormeter that tells them when it’s time to get a warrant?

For those who don’t know, the D.H. Ginsburg Aggregatormeter is a device carved from a block of wood, with a painted dial that ranges from “safe” to “get a warrant”.

It has an indicator painted on it that always points to “get a warrant”.

The implication is: if you feel you should look at the Aggregatormeter, you already know the answer.

Add Your Comment

Your email address will not be published.

Have a Techdirt Account? Sign in now. Want one? Register here

Comment Options:

Make this the or (get credits or sign in to see balance) what's this?

What's this?

Techdirt community members with Techdirt Credits can spotlight a comment as either the "First Word" or "Last Word" on a particular comment thread. Credits can be purchased at the Techdirt Insider Shop »

Follow Techdirt

Techdirt Daily Newsletter

Techdirt Deals
Techdirt Insider Discord
The latest chatter on the Techdirt Insider Discord channel...