The conclusion about a "general place at a general time" seems entirely true when you're on a highway, moving quickly and hopping infrequently to large distant cell towers. No wifi points anywhere close. Just like the chosen example.<p>I bet its entirely different when you're in any kind of built-up area. Wifi points every few hundred meters, small cell towers every kilometer or two. I bet in those situations, someone could derive a pretty close record of "your moves". Even if the individual points jump around, you're presumably hopping cells and seeing new Wifi APs every few minutes - even when you're just walking around your house or your office - and that data can be triangulated.<p>I think the OP is right inasmuch as Apple probably didn't set out to track users as much as keep track of connected wifi & cell APs. That doesn't mean the data won't be enough to track movements in urbanised areas.
The piece is specifically positioned as a retort to a somewhat sensationalist O'Reilly piece, and in that context it's perhaps decent. But this headline alone on HN is at least as sensationalist - redefining "your phone is tracking your movements between cell towers with a general accuracy of 2km or less" to "your phone is not recording your moves" is just newspeak.<p>Argue that the accuracy makes the data less usable for nefarious purposes, or argue the (much more pertinent to my mind) point that your carrier already has high-accuracy historical info and this really just puts similar historical info in your hands as well, point out that law enforcement can easily get the carrier info without ever even touching your iDevice, but don't try to claim that this is not recording location info attached to you.
A better statement is: "Apple is not <i>intentionally</i> recording your moves."<p>What they're instead doing is, when possible, retrieving cell network / SkyHook (wifi) data about Lat./Long. for towers/APs that your device can see and when it last saw them.<p>This is for the Location service that an iOS device offers, so that if you choose to provide your location information to an app and it can't get a good GPS lock - this cached information is used to provide a "best guess".<p>In addition, it's used to provide an accelerated guess as GPS gets a lock (it's the "+" in GPS+).<p>The timestamp is to provide "last best location". I'm sure the rest (MACs, tower IDs, etc.) can be used to triangulate a better fix based on what's visible and what signal strength to each location is like.<p>The device caches this information locally because the Lat./Long. of a cell tower / AP will not change - but the timestamp for the last time your phone has "seen" it could be updated, without having to re-hit Apple's servers for the details.<p>It's being done because: storage is cheap, the amount of data doesn't take much space for thousands of points, it reduces server talk, and it speeds up your GPS/location acquisition for apps that you wish to use it with.<p>Apple's only mistake is that they didn't encrypt this information. Outside of that, the only other thing they could have done would be to store it purely in RAM - but RAM is at more of a premium (in MB) than flash storage (in GB).
Interesting analysis that strongly suggests the coordinates are for cell towers, not the iOS device.[1]<p>Personally, the fact that the file is in a cache directory path, and that some people don't have much data, or any, suggests to me that some programmer forgot to trim his cache or picked a ridiculously large size before he decides to trim.<p>"locationd" wants to know the coordinates of the cell towers you communicate with in order to triangulate your position without turning on the GPS, and it doesn't want to eat the battery by querying servers all the time. That argues for a cache of the towers you frequent. It's only one bug or poorly chosen constant from there to the situation people are reporting.<p>[1] That still reports your travels in gross terms and is a problem in need of a fix.
I'm getting a 509, bandwidth limit exceeded. Here's the Google Cache: <a href="http://webcache.googleusercontent.com/search?q=cache%3Ahttp%3A%2F%2Fwww.willclarke.net%2F%3Fp%3D247" rel="nofollow">http://webcache.googleusercontent.com/search?q=cache%3Ahttp%...</a>
The only way this could be more hair-splitty is to argue "Apple isn't tracking you, it's tracking your device". Yes, there are valid reasons for this to exist. Doesn't change my user perspective that this is an electronic trail I do not want readily accessible.
There is a bit of a logical fallacy here. He says "the data is not extremely accurate", "metadata indicates apple intended to store locations of access points", "therefore the phone is not traking your location".<p>That's simply false. It is tracking your location, regardless of how accurately it's doing it, and irrespective of Apple's intentions.<p>That means someone reading the data can know roughly where you where when, the direction you where traviling in, and how fast you going.<p>Does that mean Apple set out to track you? No! But it does mean that your phone is tracking your position, all the time, everywhere you go, and is storing that data in a way that is not protected from exploration by any third party that happens to acquire access to it.<p>That's a serious bug, and is worth a little sensationalism.
I actually think my honest opinion on this fiasco is "someone can derive a user's movements from this database, but how big a deal is it really?"<p>I still think this should be fixed, Apple should explain it and release an update that pares it down to the bare minimum data for whatever function it serves.<p>However, let's honestly go through the implications of this:<p>- The user's cell provider already knows this. [1]<p>- If someone "owns" the user's phone then they can get their movement history. But that's at a point where they can track the user's current movements anyhow, so that's lose-lose there - the only difference is the historical angle.<p>- If someone steals the user's computer/phone they can get their previous history up until then. That's bad, but I bet nearly everyone has more sensitive private information available on their computer hard disk or their iPhone's internals - stuff that would be more exploitable than historical location data.<p>- Someone could maybe sneak private API calls into a legit app that sent this database somewhere else. No idea how feasible that is. However, if they can do that then it's pretty close to the "ownage" scenario described above - they can probably do anything anyhow.<p>If it comes out that Apple is sending this data back to Cupertino for some nefarious purpose then that is very bad as well, but I bet that's not the case.<p>[1] <a href="http://www.zeit.de/digital/datenschutz/2011-03/data-protection-malte-spitz" rel="nofollow">http://www.zeit.de/digital/datenschutz/2011-03/data-protecti...</a>
My guess is that this is just an implementation optimization. Probably analogous to lookupd caching DNS lookups. The developers probably didn't think anything of it.<p>Even lookupd caches could be represented in similar light: "Your Mac secretly records the websites you visit in a hidden file." It's just that we're all used to (and understand) DNS lookup caches, and locationd and location lookups are relatively young.
It remains unclear what Apple's motives were in collecting this information and regardless of how accurate the collected information is, I think the larger concern is that the database is unencrypted (although it does require root access) and is uploaded to a users computer upon backup.
How can the iPhone determine the location of a cell tower (or WiFi access point) just by receiving its signal?<p>While it seems obvious from that analysis that it is indeed logging the locations of the towers rather than the phone, I am more interested in how it derives the locations for those towers.<p>It could simply have a lookup table, but that would mean every iPhone has a lookup table of every cell tower (GSM and CDMA) as well as WiFi point in the world - with a globally unique identifier and location - as part of the OS. Which seems pretty implausible.<p>If it's doing a remote lookup, then it must be polling some service to determine the location of every CellID it seems. Something like OpenCellID (<a href="http://www.opencellid.org/" rel="nofollow">http://www.opencellid.org/</a>) or Navizon <a href="http://www.navizon.com/" rel="nofollow">http://www.navizon.com/</a>) is what I mean. If so, it <i>would</i> effectively be broadcasting your location in real-time. This is equally implausible, as it just seems like the kind of thing we'd have heard about by now through OS investigation, or even just "why is my battery draining so quick".<p>It could conceivably triangulate the tower itself, but that's implausible as a) the phone's GPS would have to be active (see battery issue above) and b) it couldn't possibly be accurate unless you were effectively spiralling around the emitter.<p>It can't be getting it from the signal itself, as "emitter location" sure isn't part of the WiFi spec and I'd be amazed if it was in GSM or CDMA.<p>How else can the iPhone know (or estimate) the GPS coordinate of cell towers?
I can't comment on the website itself somehow. But here is my comment.<p>While you may be correct (and I think you are, because Apple has previously mentioned that they use such data to map tower locations) but I have a few counter points to your article (may not refute your main conclusion):
1. Even Cell Triangulation can be way off depending on a lot of factors. I use it regularly on my Android phone with Tasker for some profile purposes and it gives me worse results most of the times than actually working with exact tower ID that I am seeing. I've seen it being as off as upto 5 kms<p>2. The location data is collected for other countries as well, not just for the parent network within US. Out of the various articles from various people, they have seen data from all places where they used cell services, including abroad like Japan, India, etc. The data only seems to be missing when they don't have a cell service.<p>3. What irks me is that why they need to store this data on the device and PC? Even if they were building their own cell tower database, it should be done and done once apple gets the data. Why would they keep a whole history about it on the phone and PC? Maybe it is an oversight? But I can't find any reasonable explanation for this.
I've been playing around with the source today (planning to take a closer look at the file itself tomorrow). While there are definitely a fair amount of anomalie, even without removing the intended obfuscation in iPhoneTracker it still tells a good story. After adjusting the accuracy of the GPS grid and changing the animation to daily, it was easy to track where I had been.<p>It would probably be hard to track to any specific address (that's what I am looking into now) but by matching date with the coordinates it was trivial to see where I went for: 4th of July, my friends bachelor party and wedding, Halloween, Thanksgiving and New Year's Eve... among other events.
I'm going to file this under "come on, are you kidding me, read the FAQ before you write a blog post."<p>The FAQ: <a href="http://petewarden.github.com/iPhoneTracker/#9" rel="nofollow">http://petewarden.github.com/iPhoneTracker/#9</a><p>The wonders of following links.
By the way, this same information is already tracked and stored by the mobile networks themselves, and can be obtained by the government with a warrant (or likely by organizations like the NSA or CIA without one, given recent precedents).<p>See <a href="http://nce.fd.org/PDF%20Cellular%20Tower%20Location%20Information.pdf" rel="nofollow">http://nce.fd.org/PDF%20Cellular%20Tower%20Location%20Inform...</a> :<p>"Cellular service providers generally retain information about phones’ contacts with towers, including which tower(s) each phone contacted during any given check-in, and which “face” of the tower(s) the phone contacted."
It looks like the original O'Reilly post was a bit imprecise.<p>On one hand, it says <i>"your iPhone, and your 3G iPad, is regularly recording the position of your device into a hidden file."</i><p>Later on, it mentions a <i>"a list of hundreds of thousands of wireless access points that my iPhone has been in range of"</i>. This suggests that the list is one of cell towers (and perhaps Wi-Fi routers ?), but not actual device locations.
Not many people seem to be noting this, but I think it bears noting that it seems very much true that <i>Apple</i> isn't tracking anything; your iPhone is.<p>There are legitimate potential worries about that, but "ZOMG Apple is Big Brother" is the kind of rhetoric that keeps people confused and afraid about security to the point that they <i>do</i> screw themselves over.
I agree. This is the cell tower data you get back from the significant change API (the low battery use location mechanism).<p><a href="http://www.cannonade.net/blog.php?id=1482" rel="nofollow">http://www.cannonade.net/blog.php?id=1482</a><p>I am not really surprised Apple doesn't throw this data away. I think they could have been a little more transparent about it though.
tl;dr... All it’s showing is cell tower location heatmap, which is anywhere within a 2 to 3 mile radius. (Basically what city you are in.)<p>Cue false outrage... Endless CNN coverage.<p>Trolling rant: Meanwhile, US phone carriers, advertisers, and the government have known your location within 9 feet, ever since the warrentless wiretapping scandal. To the point that NSA, has a direct fiber split of all AT&T customer internet traffic. <a href="http://webcache.googleusercontent.com/search?q=cache:Rm4GQZmj5aAJ:www.eff.org/nsa/hepting+eff+nsa+att&cd=4&hl=en&ct=clnk&gl=us&source=www.google.com" rel="nofollow">http://webcache.googleusercontent.com/search?q=cache:Rm4GQZm...</a> America, choose your battles and get a grip on reality.
"Apple is not storing the device’s location, it’s storing the location of the towers that the device is communicating with."<p>Oh come on. That's like saying, "I'm not laughing AT you, I'm laughing NEAR you."
Has anyone looked at the coordinates in the Wifilocation table?<p>For cell towers, iOS has access to coordinates from the tower's signal itself. For Wifi, the best approximation would be the GPS location of the device. Unless it associates Wifi APs with nearby cell towers, or "fuzzes" that location.