Slashdot Mirror
Shopping Centers Track Customers Via Cell Phone Signals
oschobero writes "According an article from the Times, customers in shopping centers are having their every move tracked. Using cellphone signals, the system can tell when people enter the center, how long they stay in a particular shop, and what route each customer takes. The system works by monitoring the signals produced by mobile handsets and then locating the phone by triangulation." The particular tracking device described by the article is made by an English company called Path Intelligence.
No, if you turn it off, it's off.
At least on every phone I've owned.
Gone!
Seriously, The Path Intelligence guys use, or at least got started using, the GNU Radio platform(which, incidentally, is really really cool and you ought to check out). http://www.wired.com/science/discoveries/news/2006/06/70933?currentPage=2 http://photos1.blogger.com/blogger/6124/1637/1600/path_intelligence.jpg http://handcircus.blogspot.com/2006/06/my-brother-in-wired.html
Now all we need is retinal/facial recognition and we'll have the perfectly offensive onslaught of advertisements available to us.
How did you like the last ad greeting you by name, John Anderton?
Want to improve your Karma? Instead of "Post Anonymously", try the "Post Humously" option.
If the mall is going to use my equipment for their benefit, I should be warned before entering the premises. I see no mention on TFA about the mall warning its customers about the tracking system , besides looking for the antennas on the walls but those can easily be concealed. Maybe someone can come up with a device that changes IMEIs on the fly creating one man stampedes/mobs
The best test environment is production. - Me
chrome://browser/content/browser.xul
Instead of walking, we could get a bunch of Roombas and glue cell phones to them.
That should take care of their system. And their floors.
There's no -1 for "I don't get it."
Which customers? Which shopping centers? ALL OF THEM? Am I being tracked?
Put on your tin-foil hats everyone!
Sigs are for Terrorists.
Whenever I read big-brother type stuff like this, I'm reminded of one of the best lectures I received regarding the direction of IT (and this was years ago)
In speaking about GIS he outlined some items that seemed very spooky and seemingly improbable things that would happen - then he discussed the results of those things occurring as if they were a given. I was skeptical that they'd even happen, but they are beginning to... stuff like this article mentions, how it will be very close to impossible to travel without a cell phone, and how that would essentially mark you (not in the crazy 666 sense) for all kinds of crap people want to sell to you.
At the end, his point was that these types of things will be reviled in name only, but once people receive the benefits of the technology, they'll love it. We're headed down this path whether we like it or not; privacy will become a very relative thing in the next couple decades. We will need to rely exclusively on the good faith of the companies that guard our information.
If you can read this... 01110101 01110010 00100000 01100001 00100000 01100111 01100101 01100101 01101011
That would defeat the purpose of a cellphone.
This is pretty cool. The website claims accuracy of 1-2 meters. If they indeed use triangulation, their equipment has to be able to measure time down to ~1/300 millionth of a second. BTW, chances are that tracking is anonymous. I don't believe phones transmit phone numbers or other private information unencrypted.
Since this article is about cell phone tracking, I thought I would mention a free GPS tracking service that we recently launched. It's called InstaMapper. There is a DIY that explains how to track a car in real-time using a $40 prepaid cell phone:
http://www.instamapper.com/diytracking.html
Under Section 5(1)(b) of the WT Act 1949 it is an offence if a person "otherwise than under the authority of a designated person, either:(i) uses any wireless telegraphy apparatus with intent to obtain information as to the contents, sender or addressee of any message whether sent by means of wireless telegraphy or not, of which neither the person using the apparatus nor a person on whose behalf he is acting is an intended recipient;
This means that it is illegal to listen to anything other than general reception transmissions unless you are either a licensed user of the frequencies in question or have been specifically authorized to do so by a designated person. A designated person means:
the Secretary of State;
the Commissioners of Customs and Excise; or
any other person designated for the purpose by regulations made by the Secretary of State.
Or:
(ii) except in the course of legal proceedings or for the purpose of any report thereof, discloses any information as to the contents, sender or addressee of any such message, being information which would not have come to his knowledge but for the use of wireless telegraphy apparatus by him or by another person."
This means that it is also illegal to tell a third party what you have heard.
With certain exceptions, it is an offence under Section 1 of the Regulation of Investigatory Powers Act 2000 for a person - "intentionally and without lawful authority to intercept, at any place in the United Kingdom, any communication in the course of its transmission by means of:
a public postal service; or
a public telecommunication system."
It is similarly an offence to intercept any communication in the course of its transmission by means of a private telecommunication system.
According to Ofcom, scanners and monitoring radios can be legally sold, bought and used in the United Kingdom, without the need to obtain a license, provided they only receive radio services meant for general reception by the public. In the UK such services include Citizens' Band, Amateur, licensed broadcast radio, weather and navigation broadcasts.
It is only illegal to use scanners to listen to licensed private services such as the police and taxi radio transmissions and other prohibited or private broadcasts not intended for the public. Listening in on such broadcasts is an offence under Section 5(1) (b) of the Wireless Telegraphy Act 1949.
In order to help the public understand what it can and cannot listen to, Ofcom publishes a Radio Authority information sheet titled RA-169.
Anyone who intends to listen to radio transmissions should be aware of the following, it warns: A license is not required for a radio receiver as long as it is not capable of transmission according to The Wireless Telegraphy Apparatus (Receivers) (Exemption) Regulations 1989 (SI 1989 No 123). An exception to this is that it is an offense to listen to unlicensed broadcasters (pirate broadcasts) without a license and licenses are not issued for that purpose.
Although it is not illegal to sell, buy or own a scanning or other receiver in the UK, it must only be used to listen to transmissions meant for general reception - Amateur and Citizens' Band transmissions, licensed broadcast radio and weather and navigation broadcasts. It is an offence to use your scanner to listen to any other radio services unless you are authorized by a designated person to do so.
So possession of the equipment is allowed so long as it is not used to listen to prohibited communications in the UK.
http://www.monitoringtimes.com/html/mtlaws_may04.html
It's been illegal to snoop on cell phone calls since 1986, and law enforcement does require permission from a judge to tap your cell phone.
And to my knowledge, digital cell phone calls are encrypted. Since there is very little of the analog network remaining, that means that essentially all of them are encrypted. It may not be the best, but it is encrypted.
You can never go home again... but I guess you can shop there.
There's no need to use a signal jammer. It's your very own phone. Maybe you've never heard of that concept, but mobile phones tend to have an option which has about the same effect on your own phone phone as a jammer, but without disturbing other people's phones: Just switch your phone off! As an added bonus, you'll also increase the battery life of your phone.
The Tao of math: The numbers you can count are not the real numbers.
Lots of fun things you can imagine doing with this :)
... the dressing room at Victoria's Secret / Stall 3 in the bathroom at Baskin Robbins / the service elevator in any place you can find with a service elevator.
... no, wait, they didn't. Errr ... 50 people just appeared spaced in a grid around the parking lot! No, they've disappeared.
Gather as many cellphones as possible (from cooperating friends etc). Put them all in a small basket.
Have them visit for a while in
Or just have people do a lot of trading, so person A keeps visiting place 3, over and over and over. (Also works with grocery loyalty oath cards.)
Have a massive "appearance" / "disappearance" fest. Hey! 50 people just appeared inside Best Buy! No
timothy
jrnl: http://tinyurl.com/c2l8yr / foes: http://tinyurl.com/ckjno5
Other things these systems could do include correlating phone IDs with missing big-ticket merchandise to identify possible shoplifters, or look for suspicious activity like repeated visits to rest rooms or other semi-private places by the same set of IDs. Combine it with video records and credit card records and you can get a fair amount of visitor identification without going to the phone company for tracing. Not enough to act, but enough to be useful to security personnel.
It's another step towards Brin's transparent society.
I don't have objections to it being done correctly. By correctly I would want the following issues to be addressed. 1. No attempts to find out who the cell phone belongs to. (No personally identifiable information). 2. The id number that the cell phone transmits is never stored in any way. The use of an internal identifying number would be acceptable as long as no link was made between the actual cell phone identification number and the internal id number is stored. 3. Every time you visit the mall you get a new internal id number. This would prevent getting information about repeat visits to the mall. My concerns about storing personally identifiable information stems from the government. The government would subpoena for the mall owners cell phone information and all sorts of fun would begin. Even if only a cell phone id number is stored it would be enough for the government to use as a starting point.
They will track you the best, because when the signal quality gets worse, your phone increases its own signal strength in order to keep the connection as long as possible.
The Tao of math: The numbers you can count are not the real numbers.
Okay, fine, so now I want to use SMS to send my shopping list to the mall, and get in return directions to the aisle and row of the widget I want, with the price displayed on the map on my phone of the mall, with directions if I ask, so I can decide which of two competing stores to go to. Better still, I would not mind if the the higher priced store might offer me a deal when they see me entering their competitor's shop. And no colluding on price, please, I will go to another mall...
Simple example: If you monitor the ways where people go, you'll know the places where most people pass, and will put those things you want them to buy on those places.
The Tao of math: The numbers you can count are not the real numbers.
Iam sure the cellphone companies will love to put a stop to a third party using their $billion privately licensed network infrastructure for commercial gain that they are not a part of.
Of course if ALL the cellphone companies have giving their blessings to recieve their frequencies then the legal threat is reduced, somehow from reading about their tech they dont have permssion.
i presume they have lawyers?, even a ham radio operator could tell you the laws on reception of signals, bottom line no permission, no reception or usage in any way at ALL
You can also enable 'airplane mode' on most phones, which turns off the radio but leaves the phone otherwise functional. Some phones behave oddly when you do this though; my RIZR's clock tends to skew by a few hours a day when I leave it on airplane mode (while I was in the hospital). Screwed with my sense of time for a while until I figured it out.
They intercept the IMEI number of the cell phone; the serial number of the hardware, not your personal telephone number. You could change the telephone number simply by unlocking the phone and inserting a new SIM card. But the IMEI never changes unless you got a new phone.
Like cable broadband networks, the actual data transferred for calls is encrypted, but the IMEI is not.
Vintage computer adverts: http://www.vintageadbrowser.com/computers-and-software-ads
> look for suspicious activity like repeated visits to rest rooms
Either you're a terrorist or you've got the runs, and we're not taking chances!
How long before there is some sort of "Drop Your Cell Phones Off Here" at the entrance to major stores and malls... kinda like how there used to be (and in some places still is) ones for weapons.
Although, obviously the stores themselves wouldnt do this, but once this gets more publicity, or more adoption from other stores, there might be some sort of Anti-Tracking organization that will do it...
"This Store Doesn't Track You"
I don't own a cell phone, and probably never will (by choice), but as anti-tracking as I am, this is the least of my worries, infact if it was "open" it could really be benificial in some cases...
"Excuse me, I left something somewhere in this mall, my Cell Phone ID# is 8675309, could you give me a map of where I was today?"
or...
"I can't find my kid, but she has a cell phone, its ID# is 1337K1D, where are they?"
But, alas, the drawbacks far outweigh the benifits as far as im concerned.
2) ???
3) Profit!
Actually, number 2 should perhaps be "Invest in iRobot Corporation." After all, monkeys don't clean up after themselves.
Weaseling out of things is important to learn. It's what separates us from the animals... except the weasel."
With most shops, they try and arrange the floor sections so that people walk through as many areas as possible. The most popular areas will be at the most inaccessible corner - Bookstores tend to have the expensive educational titles at the very back, while they have the cheap paperbacks at the front of the store.
DIY stores (like IKEA) try and arrange all the sections so that you have to walk through every section (think Koch curve) to get from the main door to the item you want to buy to the checkout desk and the exit.
Supermarkets tend to have the flowers/fruit/newspapers/magazines seem to be next to the entrance, the bakery is way back near the opposite side/end of the store, and the liquor/beer/wine is in another corner, with the frozen food section somewhere in the middle. In that way, they get everyone to wander all through the aisles, rather than just walking in and out.
Vintage computer adverts: http://www.vintageadbrowser.com/computers-and-software-ads
Article, though datelined "San Francisco", seems to refer to tracking being done in a GSM-only environment. They talk about looking at the IMEI of the handsets, which is a GSM term, and the locations mentioned seem to be in the UK.
In the US, they'd have to be decoding three to six different protocols on at least three frequency bands. Those nodes would cost a fortune. You'd have want that location information pretty badly to fund something like that. Not to mention multipath issues.
I know it would work in theory, but something tells me this company isn't tracking *all* handsets in a large mall. Of course, you'd only find that out once you pay for their reports...
The type of thing they claim, not even network operators can do, and they assign all the frequencies in use, so, they know who is who. Cell phones (GSM, at least) don't broadcast unless there's something to do, like make a call, change base station, etc. How they will monitor something that is not broadcasting?
This can only be achieved using monitoring software IN the cell phone, using network monitoring (a big subject).
I don't know what they are monitoring, but for sure, it is not GSM phones.
Math is beautiful... e^(pi*i)+1=0
I have personally seen a technology demonstration where I took the battery out of my Nokia 6288, walked into the next room, and whispered a word into the phone. I dragged my finger across the mic-hole and blew into it. When I came back, guess what I heard played back to me?
I was told that it's good for 50 meters.
I think that will screw with your shopping more than it will screw with their data.
Step 1: Buy pouch (http://www.dealextreme.com/details.dx/sku.1305 $2.85 at the time of writing w/free shipping!)
Step 2: Put phone in pouch before entering mall
Step 3: Take phone out of pouch periodically to check text messages/make calls.
Step 4: Confuse system by having phone randomly appear for short intervals around the mall.
Step 5: ???
Step 6: Profit!
A cellphone which is turned off cannot be used to listen in on private conversations. The RF section is off (and you can verify this with a simple ammeter; the RF section draws significant power). Unless, of course, the FBI/CIA/NSA/MI5 has switched your cellphone out for a specially modified one which doesn't actually turn off.
You also need to read the news.com news article linked to from other comments here. The FBI was pretty clear in its statements.
Thank you for providing the counter-example of a swapped out cellphone -- that'd a good point. But I think they don't even need to do THAT.
And an iphone is not turned off when it's turned off -- Go read the slashdot article about the guy who got a $5000 bill when it was "turned off" while on a cruise. It still checks your email, it still transfers data. I could be wrong -- I don't have an iphone. Or a cellphone. I'm not an expert. But I do rememeber what I've read that makes me NOT want to get one.
-Clio
Karma: Bad (mostly from not giving a fuck)
Blog: http://clintjcl.wordpress.com
I've often wondered about this (and most forms of advertising), but are geeks generally immune to this sort of thing. If I need something from a supermarket I will take the most direct route to the item and the most direct route to the till. I basically never buy anything not already on the agenda (though I may detour to the DVD section because the supermarkets often have stupidly cheap bargains) and NEVER browse. My wife is the opposite, she'll go for a loaf of bread and come out with a half dozen carrier bags and will take 45 minutes to do it.
Is my way an intrinsic part of being logical of thought?
It's all fun and games until a 200' robot dinosaur shows up and trashes Neo-Tokyo... Again
the system set up in malls will only activate if the phone is turned on and sending and receiving signals from the local tower.
In Hans Reisers case, he removed the batteries to avoid a 'feature' in modern cell phones whereby a phone in 'off' mode can be remotely powered up by a broad cast signal sent from all nearby cell towers, to only the specific serial number of the phone trying to be remotely activated.
but the evidence was found anyways, he really should have sunk the evidence in a body of water too deep to be located from, like the pacific ocean in a container that would sink, and never decay in his own lifetime...
if you're going to ditch evidence do it better than Hans Reiser.
https://www.gnu.org/philosophy/free-sw.html
That's the way my womenfolk shop as well. They'll have a list of things they want to get, and they will zig-zag back and forth through the shop, even if items #1 and #3 are within one aisle of each other, they will still travel the four aisles to item #2. I tend to go for the items that are most likely to sell out first, then go for the items that never go out of stock, using the same optimised rout e that I have used before.
Vintage computer adverts: http://www.vintageadbrowser.com/computers-and-software-ads
"Or, you could always take your cell phone and put it in a nice metal screen bag."
You Trust 'metal screen bags' really stop the signals? no, the phone itself detects that it's in a 'screen' bag, by the distortion of the mesh and tells the user it is off, if you truly want to build a Faraday cage, use solid sheets of Lead, as a close second use aluminum as always the thicker the better, to truly shield from all lower magnetic spectrum at least 18 gauge lead shielding should be used, to protect from the highest energy particles, you need at least 2 feet of lead, to stop the easily producible high energy particles, to stop the really rare types of high energy particles, you need a theoretical thickness of one light year of lead, but if you believe science journals, these ultra high energy particles are so rare, that the only place they can be detected is several miles underground (like cheyenne mountain) and supposedly they are almost impossible to produce, but thats IF you believe science journals. of course the real truth is that cheyenne mountain is where it is because they can easily detect the signals from all the implants more easily there, where other frequencies of electromagnetic spectrum are blocked by the natural rock formation.
since you need a theoretical thickness of one light year of lead to stop the really high energy particle transmissions by the implants, the only solution is to replace the working implant with a forgery replacement that tells them all the mind control is working, then you must be very very careful, to keep up the guise as a mind controlled member of the masses.
since the implant is based on nanotechnology, and was first brought to us by a time traveler from the year 3024 there is little hope of building your own mind control implant, fortunately the underground resistance was able to gain a few operatives in the 1940s when the implants were first being embedded in the masses, if you're lucky they will find you and choose you to receive a false implant.
If it wasn't for the underground they wouldn't have had 2006 to worry about... if you don't know what happened in 2006, then you are a fool, you don't think fuel prices went up because 'they' could no longer create an artificially low price in an attempt to use up all the energy resources of the resistance in 3024
well i've said too much and i know they know i know, but i am technically diagnosed 'paranoid schizophrenic' because of the hack to my implant in 2006, perhaps posting this will speed up my being firmly declared as such and eligible for disability.
or maybe they'll move to put me on the stronger medicines they use to keep known resistors in a hallucinogenic haze. I don't know, they put me on the weaker meds because i figured out to keep silent on what i knew in person, but those stronger meds do leave you in a haze, and they like putting people on it, when their mind control implants are hijacked or fail for a short while.
FWIW yes i take my medication, but even my doctor has told me that 'the level of meds I'm on now, will do little for paranoid thoughts' the med i was on before this wasn't even strong enough for me to not get hijacked for a 2 day period, after which a doctor took me off my medications, the underground wanted to use me, through mind control, but the blackouts associated with complete hijack (the normal mode is 'forgetfulness' 'random cravings' etc etc, the more subtle the easier you are led)
so many people buy 'solar' energy products that contain a battery that is charged by day time, running a low power LED light, Ironically because of the battery and cost of the solar panels far more energy is used than just hardwiring real led night lights... by almost 10 fold... wile also eating up the silicon of the type used to make solar panels. at all costs they will manipulate us to use up the energy so desperately needed in 3024.
https://www.gnu.org/philosophy/free-sw.html
Everyone thinks of this story in terms of privacy but no one thinks of it in financial terms: My shop usage data have great financial value (otherwise the shops wouldn't pay to install surveillance systems) and the shop's surveillance is involuntary - I am not given a choice whether to allow them track me or not, except if I avoid transmitting wireless signals while near their shop. As the data collection is not voluntary and my shop usage data have financial value, I demand payment from shops using this system. I want a share of my shop usage data's financial value.
neither of these features can be done by the mall system, since it is illegal to put a microwave broadcast device in the spectrum used by cell phones in a market without having a contract to do so. So therefor, they cannot in a mall turn on your phone to track your movement if it is turned off, Unless the system is Owned by your service provider, and they are 'leasing' the data collected to the malls, and thus are able to remotely activate said phones.
i don't think service providers would willing to sell the ability to turn an off phone on, which is a reserved feature for emergency location, for the low price that malls would be willing to pay for such data, so as such they're going to simply buy devices that can detect and identify customers and their movement data, by the cellphones people 'leave in the on position' opting out in this case, is to turn off your phone before you get to the parking lot.
https://www.gnu.org/philosophy/free-sw.html
When a phone is off, it's off. No signal, nothing. If the CIA was listening and no call was being made, the phone it self was bugged (you know, spy gear and stuff). Not because they where listening on the person while the phone was off.
Sometimes CNN is wrong or lies, choose one.
"Even easier than airplane mode, now with less fuss and bother, we bring you the cell phone jamming pouch! It's so simple, I believe even a blindfolded lab rat could figure out how to use it."
leaving your phone on in said pouch will turn it to 'high power transmit mode' which will kill the typical cell phones battery within an hour.
maybe you can disable this power draining feature in some phones, but i have not yet figured out how on my own phone.
BTW the best way to test your phone for if 'high power' mode is on is to stick it in a microwave oven, if it still gets bars after a minute, it's automatically going to 'high power mode' and yes, microwave ovens don't stop much microwave energy, they are considered safe, because people in the airforce have for years been standing much much closer to much much more powerful microwave generators for many hours at a time... in fact i've read that the first discovery of microwave energy for cooking was an accidentally melted chocolate bar, then intentionally popped popcorn, and finally an egg, which exploded.
https://www.gnu.org/philosophy/free-sw.html
If you think this is true enough for it to affect your behavior, do some homework first. Otherwise, treat major media companies purely as entertainment. Hell, they should all be required to carry a warning label: "For entertainment purposes only." I mean, why else would they have the doings of celebrities on there? That stuff isn't news.
Question everything
Unless you don't live in the US, which of course covers MOST people.
You clearly have no idea of the technology involved, do you?
The phone only needs to wake up long enough to send one packet to some towers, then turn off. This is especially true in GSM-land; while Sprint and Verizon were able to specify phones with GPS in order to satisfy E911, this didn't really fly for the GSM providers, so they use TDOA - Timed Difference of Arrival. It works like GPS in reverse; the time it takes for the packet to travel from your phone to the towers is measured, at least two signals are compared and a little "magic" (we now call it "signals processing") thrown in, and they can get a pretty good fix.
All your phone has to do is wake up for a couple of seconds every minute and fire off a single ping, and that information can be used to track you. I know this technology is already in common use among GSM providers in the US; not sure about the other guys.
The ONLY reason that cellphones can't be used in the air is the havoc it would wreak on the cell network.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
No one is recording a telephone conversation, just triangulating its source location.
On one hand, it seems like bad form. On the other hand, you're broadcasting EM in their building and asking them not to pick it up is stupid. Finally, this will be done in every shopping mall in the world using cameras sooner or later, so who cares?
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
...Assuming you have a cell phone that can really be turned OFF.
This will allow you to use your cell phone while in the mall without giving them any really useful tracking information.
Use the cell phone in only one place, near the mall entrance. Turn it off as you leave the mall entrance area. They can tell that a cell phone ID 31784908 came into the mall at X time, was in the entrance at Y and Z times, and left at W time. If you're paranoid (I don't blame you) they could link the cell phone ID to your name through the service provider and tell that YOU were in the mall at these times, which is still a lot better than giving away a detailed map of your shopping activities.
Get used to using your cell phone's radio judiciously in the future. Software plugins to allow the radio to be disabled on command, and give some sort of warning signal when it's on, might be a popular modification.
"When information is power, privacy is freedom" - Jah-Wren Ryel
Good luck finding a local d.a. willing to indict a cop for "doing his job". Might I recommend RSS-subscribing to BadCopNews.net for a few months? It'll wake you up to the way things work.
-Clio
Karma: Bad (mostly from not giving a fuck)
Blog: http://clintjcl.wordpress.com
Cite? Because that's BS.
If your phone can be turned on by a radio signal, that means that the RF receiver and amplifier have to be powered up in order to receive the signal, and some processor has to be powered up in order to analyze the incoming signals and determine if the "power up" signal has been received. The technical term for a phone in such a state is "ON".
Just because something is off doesn't mean it is off completely. In fact if you turn off everything in your house, you'll find that you're still consuming considerable electricity from most everything in the house.Yes, many household electronic devices have a "soft off" mode. Battery-powered devices work differently, because it's a bad thing for a battery-powered device to continually draw down its battery while turned off. Actually powering up the RF equipment in the phone would drain it just as fast as if the phone were on but not being used for talking.
If you have a cell phone that has an alarm that can power up the phone at the preset time then your phone isn't really off.Not true.
Many small CPUs, like the ones used in phones, have a timer circuit that stays active, drawing a miniscule current -- one that the battery could supply for decades. When the phone is off, that circuit is the only thing active and drawing power. The phone IS off, the RF transciever is off, the CPU is off, any DRAM is off and not being refreshed, the display is off, the keypad is off -- the fact that one tiny circuit in the CPU is running a timing loop and will trigger a relay to power the phone up at a preset time does not mean that the phone is on.
If you have a Nextel phone, it may have two way radio features.Only when it's turned on.
If you have a phone that does more than than just make calls and save phone numbers, has GPS locater in it, etc. then your phone may not shutdown completely off.Nearly all phones these days have a GPS reciever in them, but not only are the GPS units not powered up when the phone is off, they generally aren't even powered up when the phone is on, because a GPSr sucks way too much juice and would kill your battery in no time. Normally, the GPSr only powers up during a 911 call, except in phones that give the user access to the GPS data, and then the GPSr turns on whenever the user turns it on.
My phone [...] doesn't have a GPS locater.Are you sure about that? I believe that all phones made within the last three or four years are required to have a GPS receiver in them, for emergency use.
I don't see how these malls can track every cellphone user.Oh, I can. I actually worked on a project for Sprint to enable tracking of employer-issued phones as a service, so that companies can track their delivery drivers, etc., while on their routes without adding additional equipment to the trucks.
That project only used tower triangulation for most phones (since the GPS receivers in them are usually off), and was still able to locate the phones to within 100 yards. I can easily see how putting antennas at strategic locations in the mall (kind of like passive picocells) would make it possible to localize every powered-on phone in the property to within inches. Phones don't transmit continuously when not in use, so they would only get a position update every 10-30 seconds, but that's more than enough to follow customers' movements with a high degree of accuracy. When someone is talking on their phone, of course, then you'd get continuous coverage.
Hmmm... might be useful. For malls that contain movie theaters, rather than trying to block cell signals in the theaters, maybe they should just notify theater management whenever someone answers a call. Someone could be sent in to escort the offending patron out. Might get false alarms from iphones and blackberries, though; downloading e-mail.
Note to ACs: I usually delete AC replies without reading them. If you want to talk to me, log in.