My friend Pete Warden does a splendid job of data mining, of analyzing the information that companies make available and/or track, but without telling us exactly what they’re doing. His last adventure was with Facebook, where his data analysis got him into hot water with the notoriously lax company (see his blog post I got sued by Facebook).
This time he and fellow researcher Alasdair Allan have stumbled into something rather astonishing: a time-based archive of iPhone lat/long locations where you’ve used your phone. Better yet, they wrote an open source app called iPhoneTracker that lets you visualize the data so you can understand what’s going on. A caveat: iPhoneTracker is quite clearly not intended to be a polished application with a fully implemented interface but rather a tool to let you see your own tracking information. It reveals alarming data pulled out of your primary iPhone backup file.
Here’s the result of running iPhoneTracker on my own backup file:

iPhoneTracker Data Sample, Southern California

I’ve been using the phone throughout Southern California in the last month or so, but had no idea that the device was logging my locations over time. As you can see, however, it is, and the darker the color, the more cellular network checkins happened at that spot.
Yikes.
As other commentators have pointed out (see here, here and here), at a minimum this data should be stored in an encrypted format, but the fact that it’s logging this information at all is troubling. What’s the point of it? Why use storage space for this obviously rather large dataset? Why not give me the option of disabling this feature for increased privacy?
More importantly, what does Apple do with it when I sync, when I take my iPhone in to the Apple Store for service, when I trade in the phone for a newer device?
I realize that it’s not the end of the world and I’m not doing my Chicken Little impression here, but really, when you use your phone as you travel around, do you have the expectation that it’s tracking your every move in an easily accessible format?
Imagine those divorce fights in court… “according to your phone, you were at Tony’s place from 3-6pm every day for the last month!” “According to my WHAT?”
I’m interested in hearing an explanation from Apple about what’s going on, and even more interested in an update to iOS that lets me either disable this feature or at least encrypt it so that my privacy is a bit more assured if I lose the device.