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Cops' Warrantless Cell Phone Tracking Now Better Than GPS
Sparrowvsrevolution writes "On Thursday, the House Judiciary Committee held a hearing to discuss a proposed bill to limit location tracking of electronic devices without a warrant — what it's calling the Geolocational Privacy and Surveillance Act, or the GPS Act. Ahead of that hearing, University of Pennsylvania computer science professor Matt Blaze submitted written testimony (PDF) telling Congress that phone carriers, as well as the law enforcement agencies with which they share data, can now use phones' proximity to cell towers and other sources of cellular data to track their location as precisely or even more precisely than they can with global positioning satellites. Thanks to the growing density of cell towers and the proliferation of devices like picocells and femtocells that transmit cell signals indoors, even GPS-less phones can be tracked with a high degree of precision and can offer data that GPS can't, like the location of someone inside a building or what floor they're on. With the GPS Act, Congress is considering expanding the ban on warrantless tracking of cars with GPS devices that the Supreme Court decided on in January. Blaze's testimony suggests they need to include non-GPS tracking of cell phones in that ban, a measure law enforcement agencies are strongly resisting."
...You can't have both.
The cell tower nearest my home is about 2 miles by crow, but 15 miles by car, on the other side of the reservoir. GPS is much more accurate.
Don't they use your distance from multiple cell towers to triangulate your position?
We, the consumers, pay good money for the hardware in a smartphone, including the GPS geolocation capabilities. Then some government goons come along and say "Ha ha! We'll track your location using the GPS electronics in your phone!" ------- Same with Facebook. We, the users, make Facebook a great, big site with our data and our invested time. Then the government goons come along and say "Ha Ha! We'll find out everything we want about you by poaching your Facebook data!" ------ This particular decade has very much started on the wrong foot, with regards to personal privacy and somesuch. -------- How much worse can this all get? Will we be required by law to give up ALL PRIVATE DATA because the government likes to have it? -------- These laws and personal data tracking policies are just wrong.... wrong, wrong, wrong....
Why did the chicken cross the road? Because Elon Musk put an AI chip in its head.
The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.
Every time we pass a new law we water down the constitution.
"papers" - is not strictly paper. it is where their data is stored.
"effects" - whatever they have
"houses" - where they store themselves and their stuff.
"persons" - they themselves
what more is needed?
comment directly in my journal
Unlike GPS devices covertly installed on your vehicle by police, cell phones are in the user's control. You don't have to leave it turned on all the time. In particular, if you are doing something private, like visiting your mistress, you can simply turn the phone off before driving to her apartment. And if you're afraid the phone will still leak location information while in standby or power-off mode, you can simply remove the battery.
If I can be modded down for being a troll, can I be modded up for being an orc, or a balrog?
This seems obvious to me, but bills like this should be formulated in terms of what they actually do, regardless of the technology used.
In this case, the bill should simply state that a warrant is required when someones location is actively monitored within a certain precision for a certain time period.
Same with laws around cookies, which is a topic among lawmakers in some countries. Instead targeting cookies, these laws should address the fact that a user is uniquely identified across sessions and/or websites. Cookies are just one way to achieve this, but there are others which do not even require cookies, such IP number in combination with all sorts of data such as browser agent, os, screen resolution etc. etc. that makes any user pretty much unique even without cookies.
My karma ran over your dogma
The cell tower nearest my home is about 2 miles by crow, but 15 miles by car, on the other side of the reservoir.
We're talking about radio waves, not vampires. They cross water and don't follow the road.
Your cell phone pings at least three cell tower (if just at range) and selects strongest one of them.
And even that your cell phone does not connect to cell, it does not mean cell have not received its signal. Cell phone simply rejects the connection either knowing it can not boost signal so it is too weak or it is just so weak that even max boost it can not hold the stable enough connection to cell.
At country land GPS is more accurate (few meters at starts but even few centimers at longer time when holding at same position, depending how accurate the clock is in device) but even with cell towers (if you just get at least three or two longer time) you can get location few tens of meters or even the estimation of the area where you can be.
GPS is great for the user. As user is the one who gets positioning as well, not just carrier. So user can give that location information to services trough data connection to get more nice features from the phone.
But really, phone without GPS doesn't mean you can not be tracked.
That is one reason why no one at battlefield is allowed to carry a own cellphone because at electronic warfare, such device is bright like a smoke grenade at daylight. Every device emmiting signal can be detected and pinpointed its location.
Presumably they have more information than just which cell tower you are most strongly connected to. Cell towers generally have directional antennas, and have more of them in denser areas, so they will have a pretty good idea what direction from the tower you are in. Then they measure the signal strength required to reach you, and that gives an approximate distance. If there are multiple antennas on the tower, they might even get an idea of what environment you are in based on multipath reflections and stuff. Take the heading/distance data from a couple of towers, and you can get a very accurate position without being anywhere near the towers themselves.
"Except that surveillance, simply having an approximate idea where you are, is not now, and never was a search." Incorrect, if you read the decision on GPS, the problem was not with knowing where people were, either very specifically, or generally, but with the amount of time that knowledge was available. The previous decision makes it quite clear that even a general knowledge, over anything other than an incidental period of time, is a violation.
Correct. The police should be more constrained in their actions than the average citizen. Unfortunately we've allowed things to get turned on their heads.
"Kidnap"? "obtaining a warrant"? Are you trolling or do you really think law enforcement would ever be expected to wait to get a warrant before rescuing a kidnap victim?
do you really think law enforcement would ever be expected to wait to get a warrant before rescuing a kidnap victim?
Only if they want to convict the kidnapper. Using warrants and following the law are sort of important when it comes to convicting someone of a crime.
WTB [sig], PST!!!
do you really think law enforcement would ever be expected to wait to get a warrant before rescuing a kidnap victim?
Only if they want to convict the kidnapper. Using warrants and following the law are sort of important when it comes to convicting someone of a crime.
You're not talking about looking for evidence of a commited crime, but a violent crime (murder, rape, kidnapping) in progress. There's a very big difference.
Law enforcement also lives in the 21st century. How long does it take to call someone to get a warrant faxed/emailed to you?
Presumably they have more information than just which cell tower you are most strongly connected to. Cell towers generally have directional antennas, and have more of them in denser areas, so they will have a pretty good idea what direction from the tower you are in.
That is exactly right. Each cell tower has 2 - 6 cells, the borders of which are usually measured somewhat approximately by the operator. So they know which cell you are in, which tells them the rough area around the cell tower that you are in.
They also have the ability to measure round-trip time for signals sent to your phone, giving a rough estimate of the distance from the tower to you, inside your cell (this actually becomes less accurate when signal reflection is an issue).
Finally, the cell phone constantly measures _all_ cells it can find. Not just the ones belonging to your operator, but other operators as well, including (if the phone is capable) 2G, 3G and 4G cells. All this is reported back to the radio network controller to assist with handover decisions between cells, so your operator (and thus anyone else with enough authority) can access this information.
mov ax, 4c00h
int 21h
When E911 was mandated and everyone had to be able to provide the position of a phone calling 911 to the emergency services, the original solution was that every phone was going to have to have a GPS in it. A lot of them do (and did) have a GPS chip, even ones that don't let you get access to the positioning information. But many providers didn't want to pay for that chip until the user was really going to be doing something with it that they would somehow get paid for so they went another way: with Differential Time Of Arrival, or DTOA. GPS frequently doesn't work when you are in a building but DTOA doesn't care about a few walls as long as it has signal because they don't slow the signal down much compared to the time it spends passing through air.
The nifty thing about DTOA from a technological standpoint is that cell sites tend to have sectored antennas, so you only need two of them to triangulate a target, and even one site is going to significantly restrict your search area, to a relatively small arc.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Your cell phone pings at least three cell tower (if just at range) and selects strongest one of them. And even that your cell phone does not connect to cell, it does not mean cell have not received its signal. Cell phone simply rejects the connection either knowing it can not boost signal so it is too weak or it is just so weak that even max boost it can not hold the stable enough connection to cell.
I live in a ravine a couple of miles from the nearest line-of-sight cell tower, and reception there is so poor that I had to install a signal booster to have even the proverbial snowball's chance of getting reception. Even with the signal booster, I've watched various geolocation apps* (with GPS turned off) try to locate the position of my cell phone. It's quite humorous to watch my position jump by several miles while I'm sitting in my living room. My point being, while I agree that it's possible to be tracked through cell towers alone -- and possibly even very, very accurately -- terrain and other factors can drastically affect the accuracy of the geolocation.
*Yes, I understand that an app trying to determine location by measuring the signals from cell towers is not exactly the same thing as the cellular service provider determining location by seeing which towers can see you, but the point still stands -- terrain affects the ability to perform geolocation.
MCSE? No, sir...I don't do Windows. Yes, I am an idealist. What's your point?
Does one success make up for the raids on wrong addresses that have occurred?
http://www.cato.org/raidmap/