31–40 of 81 posts
http://www.cannonade.net/blog.php?id=1482
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.
Earlier quoted context omitted.
The author says he was using his phone and the GPS often. If they wanted to track your moves and you have turned on the GPS, why doesn't it just, y'know, use the GPS data? Instead Apple tries to track your moves using cell towers? Seems like the only way this would be a record of your moves would be by coincidence.
My understanding is hte iPhone doens't actually have a GPS receiver in it at all. It only uses a fuzzily defined "assisted GPS" which is basically based completely on 3g towers. They don't use the GPS satellites at all.
The original iPhone had no GPS and always used cell tower triangulation. This varied a lot - I remember in Manhattan, NY it could track me almost to the street number; on the other hand I once turned it on in a moving car in rural NSW, Australia and it drew a circle approximately 500km in diameter.
Interesting analysis that strongly suggests the coordinates are for cell towers, not the iOS device.[1] 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. "locationd" wants to know the coordinates of the cell towers you communicate…
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. 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…
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. Argue that the accuracy makes the data less usable…
Is that sensationalist? Or, does it represent the most logical explanation of this story from a technical and engineering background?
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.
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.
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 (http://www.opencellid.org/) or Navizon http://www.navizon.com/) is what I mean. If so, it would 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".
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.
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.
How else can the iPhone know (or estimate) the GPS coordinate of cell towers?
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 do screw themselves over.
A better statement is: "Apple is not intentionally recording your moves." 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. 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 c…
Does the iphone even have real GPS? I believe it uses the cell tower info only.
They use an A-GPS chip. The "A" in A-GPS stands for assisted, which means it can be assisted by the cell towers to help find the GPS satellites more quickly. Because of the connection with the cell network, some confuse its capabilities with plain triangulation. It will continue to function as a plain GPS device in the absence of cell service, however.
Most of the points on my map correspond exactly with known locations of my carrier's towers, so the explanation makes sense. However, there are dots in locations where there are no towers. I don't think it is WiFi locations because I do not see any of the places I commonly use WiFi.
Earlier quoted context omitted.
The point I made in another thread on this: http://news.ycombinator.com/item?id=2468950 Basically by having it stored locally, it lowers the barriers to accessing data, so that it is no longer restricted to law enforcement people seeking telco data. That changes a lot of things. For instance imagine you're a police informant or undercover cop: a technically savvy mob would be silly not to hoover up the location data…
For instance imagine you're a police informant or undercover cop: a technically savvy mob would be silly not to hoover up the location data of everyone in their org, Sure, but if they have root or physical access to the phone (which they need) they can install a realtime tracking snooper to follow you around instead. I agree this lowers the barrier, but fundamentally it seems to come down to - if you don't want peopl…
These days, even devices seem to have ulterior motives beyond simply being useful to you. It's crazy. The EFF's "traitorware" is appropriate here.
The FAQ: http://petewarden.github.com/iPhoneTracker/#9
The wonders of following links.