How Location Services Works
After iPhone’s location tracking hit the airwaves on April 20, 2011, Representative Edward Markey (D-MA) and Senator Al Franken (D-MN) had a few questions for Apple’s then CEO, Steve Jobs. Apple responded (admirably quickly) with a software update to the iOS 4 which came out on May 4. iOS 4.3.3 dramatically narrows the tracking capability and answers several of Frankens and Markey’s concerns.
Q: What location data does my device keep?
Latitude and longitude coordinates with a time stamp.
Q: Are the coordinates the exact location of my device?
Not quite, but possibly pretty close.
The official purpose of the tracking is to aid Location Services in triangulating your device’s location based on geotagging nearby Wi-Fi hotspots and cell towers. This should limit the specificity to how far you happen to be from the nearest cell towers.
However, the records show multiple hotspots logged for each cell tower logged. It is conceivable that your location could be further narrowed down and deductively found. Check out this visualization of one iPhone user’s road trip to New York.
Q: How often does it record my destination?
We don’t know specifics…but pretty often. There is currently no obvious pattern to times when the coordinates are recorded.
Q: Where does this data go?
It’s stored only one place: an encrypted root file on the device itself. Apple does ‘crowd-source’ location data to assist other projects, like an upcoming traffic app. However, anything that could link you or your specific device to the data is removed during retrieval.
Q: How long does it keep this data?
Q: Can I stop it?
Yes. Turn off Location Services by going to Settings > Location and turning Location Services off. Unfortunately, this will limit functionality of applications which rely on location information.