Forensic researcher Alex Levinson has discovered a way to map out where an iPhone has been. The information comes from a location cache file found on an iPhone (Library/Caches/locationd/consolidated.db).
In practice, this file contains your travel history.
It should be noted that this file can't be accessed by third-party apps on an iPhone, as you need root rights to reach it. However, the file is copied to your PC or Mac during standard iPhone sync operations and is accessible from there.
Yesterday, security researchers Pete Warden and Alasdair Allanreleased an application that can take such a file and show your movements on a map.
Now, this sounds bad from a privacy viewpoint. For example, authorities could gain a court order to do a forensic examination on your phone to figure out where you've been.
But why is Apple collecting this information to begin with? We don't know for sure. But we're guessing it's likely related to Apple's global location database.
Like Google, Apple maintains a global database of the locations of Wi-Fi networks. They use this to get an estimate of your location without using GPS. For example, if your handset sees three hotspots which have MAC addresses that Apple knows are within a certain city block in London, it's a fair bet you're in that city block.
We know how Google collected their location database: they recorded them world-wide while they had their Google Maps Street View cars driving around the globe.
However, the Skyhook database is expensive. So beginning with iPhone OS 3.2 released in April 2010, Apple started replacing the Skyhook location database with their own location database.
And the real question is: How did Apple create their own location database? They did not have cars driving around the world. They didn't need to. They had existing iPhone owners around the world do the work for them.
If you run a modern iPhone, it will send your location history to Apple twice a day. This is the default operation of the device.
How can they do this? By asking for your permission first. There is an opt-in process during initial iTunes installation, but the prompt is highly misleading:
We believe the new secret location database found on the devices is connected to this functionality. Apparently iPhones always collect your location information, even if it's not getting sent to Apple.