There has recently been a lot of noise about a tool made by Alasdair Allan and Pete Warden: every iPhone is tracking its owner's movements all the time. For the record, the existence of this database on each iPhone with iOS 4.x has been documented for several months already. And it's not really surprising... Remember Eben Moglen's talk at FOSDEM 2011?
Now, time for a confession: I have an iPhone too. It's a nice, mostly useless device, but it becomes quite fun to use once you jailbreak it. And since I jailbroke mine, I can have fun with it. Now, let's have fun with this geolocation database.
Accessing the geolocation database...
First, ssh into your jailbroken iPhone as root (or mount it with ifuse:
--root /path/to/mountpoint). The DB is stored in the
/var/root/Library/Caches/locationd folder and is named
as explained on the iPhone Tracker page. On my phone, it's a 5.4 MB file.
You can copy it to your computer (using
rsync, or just
cp if you're
If you're curious, you can then investigate the content of this file using
sqlite3 or a GUI such as sqliteman. Here are a few interesting tables:
The first one is the one used by Alasdair Allan and Pete Warden in their "iPhone Tracker" tool. On my phone, there are 2,624 records in this table (timestamp, latitude, longitude, altitude, plus some other columns), the oldest one are 2.5 months old (February 5th -- FOSDEM!). It would seem that these records indicate the positions of cell towers rather than your own, but this can only be guessed since you can't have a look at the iOS source code...
The second table has a similar structure, but apparently a different content. I did not investigate further (yet).
The last one is a little different:
wifilocation. It stores the position of a
lot of MAC addresses (with, of course, an associated timestamp). I don't know if
these are the MAC addresses of some wireless access points or the MAC addresses
of wireless clients, but given that on my phone there are 35,770 records
since February 6th, I doubt these are just access points.
...for fun and profit
The iPhone Tracker seems to be a very nice program, but it's for Macs only. So I hacked a little Python script that can read such a database and produce a KML file that can be then viewed using Google Earth.
./iphone-tracker.py path/to/consolidated.db > output.kml
The result can then be opened in Google Earth. The positions are grouped by day to avoid having 2500+ points overlapping on a map.
It can be seen, as described by the researchers who first found out about this, that the stored positions are far from being precise. The recorded timestamps are very approximate too. But the simple fact that so many data are stored about one's location is really concerning.
Several months ago, someone also made a web viewer where you can upload you database file and see the result in Google Maps (in French).
As far as I know, Apple has not made a public statement about this little controversy yet. But I'm really eager to see what they will tell about it -- if they care to tell something about it.
I'm also deeply concerned about the
wifilocation table of this database,
which, in some aspects, is much worse than the
celllocation table (no need for
your phone to store that: your network operator already has the data, and it's
probably far easier for your government to ask them than to get access to your
If it contains geolocation data of wireless access points, this could cause problems similar to what Google encountered in Germany, when Google Cars were gathering data about wireless networks in addition to the Google Street View pictures.
But if the
wifilocation table actually contains the last seen location of
wireless clients, it could mean that your phone can be used to prove that you
were close to a specific person (identified by his phone wireless MAC address)
at a specific moment. And, for some persons, in some countries, this is a
serious reason to worry.
If you wish to disable this database on your (jailbroken) iPhone, you may use this workaround.