There’s a Mac desktop iPhoneTracker.app which displays which cell towers your iPhone was in communication with — on a map, by date.
The image above shows how I was tracked from February 16th, 2011 on a trip through Amish country (the actual trip took place from Friday 18th through Sunday 20th, so the app reads forward for a period from the date you currently have selected in the bottom slider).
Clearly my iPhone is not logging my location based on GPS: It’s a pegboard everywhere I look when I zoom in close, here on my home town location of Huntington on Long Island. These are not continuous tracks but broadly scattered breadcrumbs. I don’t know if this is how it’s really recorded in the Location History db or whether it’s an artifact of how the iPhoneTracker app is interpreting the data. If I had this information earlier, however, I would have easily been able to prove my case for a free AT&T MicroCell at home. There are clearly very few cell towers near my home which the iPhone can lock onto!
Sure, your cell phone service provider keeps similar records on the other side of their firewalls, but it’ll take a court order to get at it. Pete Warden, the iPhoneTracker.app developer, says “by passively logging your location without your permission, Apple have made it possible for anyone from a jealous spouse to a private investigator to get a detailed picture of your movements” — by simply getting at the computer you sync your iPhone with.
You could, of course, choose to optionally Encrypt iPhone backup through iTunes (and not save the password in your Keychain) and Auto-Lock your iPhone with a Passcode Lock. I’m not convinced that turning all Location Services off will stop writing to this file* — since servicing the iPhone is not amongst the individual apps you can deny location services to.
Before you rush out to swap your iPhone for an Andriod: They’re tracking your movements too — but in a cache file that eventually overwrites itself.
To the question “Can Apple locate me based on my geo-tagged Wi-Fi hotspot and cell tower data?’ in Apple recent statement on this subject, they answer “No. This data is sent to Apple in an anonymous and encrypted form. Apple cannot identify the source of this data”.
David Pogue writes in The New York Times that Apple “revealed something else your iPhone is tracking: traffic data (presumably measuring how fast your iPhone is moving when it’s on roadways). ‘Apple is now collecting anonymous traffic data to build a crowd-sourced traffic database with the goal of providing iPhone users an improved traffic service in the next couple of years'”
Apple is probably just guilty of bad disclosure, data retention policies and sloppy coding — this should have been a short lived cache file with an option to delete in Settings.
*Update 5/25/2010: The Wall Street Journal tested this last concern and found my suspicions to be true IPhone Stored Location in Test Even if Disabled, turning off Location Services does not stop the iPhone writing your location to its log file.
… or maybe Apple had designs on this location history database driving a new type of geo-location aware app, according to this recent Apple Patent Application 2011/0051665 (also as a .pdf here 2011/0051665) which specifically mentions using the location history database …
“A location aware mobile device can include a base-band processor for communicating with one or more communication networks, such as a cellular networkork, WiFi net-work. In some implementations, the base band processor can collect network information overtime. The networking information can be converted to estimate position coordinates (e.g. latitude, longitude, altitude) of the location aware device. The position coordinates can be stored in a location history database on the location aware device or made accessible on a network.
A user or application can query the location history database with a time stamp or other query to retrieve all or part of the location history for display in a map view. In some implementations, the size and “freshness” of the location history database can be managed by eliminating duplicate entries in the database and/or removing older entries.The location history can be used to construct a travel time line for the location aware device. The travel time line can be displayed in a map view or used by location aware applications running on the location aware device or on a network. In some implementations, an Application Programming Interface (API) can be used by an application to query the location history database.
In some implementations, the location history can allow users to tag photos or other content taken by a device and to synchronize the content with the location history using time stamps. This can allow the user to augment a travel time-line with the content, for example.”
Suggested reading: Pete Warden’s FAQ | Pete also worked on similar visualising software behind this story Visualising radiation leaks from the Fukushima nuclear power plant in the Guardian | Cellular Sherlock’s iPhone iOS4 GPS Data | Coyote Tracks’ Don’t panic, but look a little nervous | Andy Ihnatko’s Celestial Waste of Bandwidth (BETA) post Hey, wonderful: there’s a location-tracking file on my iPhone | Alex Levinson’s 3 Major Issues with the Latest iPhone Tracking “Discovery” | The Read Write Web’s Android Phones Track Your Location, Too | Sean F. Morrissey’s iOS Forensic Analysis on page 335 under consolidated.db “potentially one of the most forensically rich files an analyst can use” – published December 27, 2010. Oh dear, us bloggers are late with the news again, huh?
Related story …
The Michigan State Police (MSP) are routinely siphoning off cell phone data from “motorists stopped for minor traffic violations”. There’s little doubt they know about this particular iPhone log. The American Civil Liberties Union (ACLU) asks MSP for more information on their use of this technology — MSP wants a half-million dollars (half of that in advance) to reply. Speechless!
Suggested reading: Apple Q&A on Location Data | ACLU Seeks Records about State Police Searches of Cellphones | The ACLU’s letter to the Michigan State Police enquiring about their use of CelleBrite technology | The Truth About Cars reports Michigan: Police Search Cell Phones During Traffic Stops | David Pogue’s Wrapping Up the Apple Location Brouhaha in The New York Times