95% of the mobile users can be uniquely identified from location data

by: Gary SimsApril 1, 2013

red dots on mapIt isn’t hard to think of a dozen films where at some point in the story a tracking device is placed on a person, car or ship so that someone can keep tabs on them. Well, that might be fiction but the truth is that millions of people willingly carry around tracking devices every day – their mobile phone. New research published in Nature has shown that by cross referencing location data with other freely available data sources it is possible to track 95% of mobile phone users using what is meant to be anonymous location data!

The research is full of some heavy statistical analysis of around 1.5 million mobile phone users who had  the location of their nearest cell tower recorded every time the they interacted with the phone network (by making a call, receiving an SMS and so on). The data was recorded in 2006 and later analysed. The researchers found that if the phone interacted with the carrier’s network once an hour it is possible to uniquely identify 95% of the individuals.

The idea is basically this, if I am in location A and receive a call then the anonymous data shows approximately where the call was received and a dot is placed on the map. If I then move to location B and receive another call, that call appears as a new dot on the map. But the dot from location A has now gone. By tracking all the other dots and by a process of elimination it is possible to work out that the phone used to receive the call at location A is the same phone now in location B. If either location is a known address like my house or my office it is quite easy to use other data, like a voters list, to start linking the phone data with an individual.

Worried? Let me know below.

  • Faiz

    Meh. It’s inevitable.

  • MasterMuffin

    If I had done something that would make the nations want my head (nothing yet, hopefully), I would just put my phone on airplane mode and call as rarely as possible/from public places. Not worried (yet)

    • In some countries you only need to hold different religious views than the government to become an enemy of the state.

      • MasterMuffin

        Finland is not THAT backward :D

      • I once threw an egg on a guy, who’s uncle was a beggar but he licked the dust off a duke’s nightgown, a fact watched by security who threw the beggar in a cellar with a snake. The snake was arrested for wagging its green tail on a red traffic light that caused the senator’s driver’s daughter to pedal forward in her bike and got hit by a bus. That bus was supposed to reach Trafalgar Square at 4pm and since it didn’t, Little Johnny missed his deadline of handing over two dead eagles to Marty Two Toes – the local gangster, who at that time was being beaten up by local wrestler for oggling at his wife who in turn got furious that he failed to produce the ransom of 2 dead eagles and cut off one of his two remaining toes and now Marty was no longer Two Toes which made him so mad that he murdered Little Johnny’s hamster which was witnessed by the CEO of Apple’s Janitorial board and he in turn had a heart attack which was misunderstood by Apple CEO that Samsung had given him a dose of “That Which Must Not Be Named” and ended up suing Samsung 1 Billion over a reported “Rectangle Copy” scam which now everybody knows is BS, so Apple is planning to go after the root cause. I made a phone call right after throwing that egg to check on my grandma. Now am I in trouble? Should I change my number?

        • Mike Reid

          Serious trouble.

        • Yes you’re in trouble…I would call your nearest mental institution because obviously you have some serious issues…

          • I quote Sheldon Cooper.. “my mother had me tested, and…” :-D

  • jose Mendoza

    this is why I usually un tick the “send anonymous anything to improve whatever”. A lot of these companies do in fact have thier sneaky ways of keeping track of those who want to share information with them. and even if I uncheck that box, I still have question if the device isn’t doing something else it wasn’t advertised it was supposed to do. thank goodness for open source software.

    • Exactly, that is a good example of an app sending “anonymous” location data, but the correlation of that data can yield remarkable accurate results.

  • Not sure if serious

    • Not an April’s fool… This is real!

  • dudi

    but you either need (a) location data from the carrier or (b) an app installed on the device that collect the location data. to get (a) is illegal, so you need to pay someone. so if you pay, just get the details that you need… to get (b) you need to convince the user to install an app- but then you can get many more useful details…

    so, very interesting research, but what’s the point (at least I didn’t get it)

    • GuyOverHere

      What he’s saying is that whenever a phone does anything like send texts, send calls, or receive calls, location data is sent to the nearest cell tower. The company that owns that cell tower can, basically, use the location data to make a connection between the device and you. Hence, they can find your workplace, your home, and other places you go.

    • The point is that even if anonymous data is collect (with any records of IMEI or phone number) etc, you can still be tracked.

      Also (according to the report) it is estimated that a third apps available in Apple’s App Store access a user’s geographic location… I guess the number would be similar for Google Play.

      I am sure there are lots of apps which send anonymous location data as part of their normally running. Most photos which are uploaded include a geo tag!

  • Fredrik Claesson

    Probably april fools!

    • Would be nice if it was… but no this is real.

  • What have you got to be worried about.It does not bother me in the slightest. I would love to be put back in the matrix !

  • loneone

    Its just a shame that people can not see where all this is headed. Your right to privacy is going out the window and people are letting it happen with no concern.

  • Nate

    I have worked with cell tower location information and because it is collected using cell tower triangulation, the horizontal accuracy of location data is anywhere between 700m to up to 5000m. It is very difficult to figure out exactly the identity of the person based on anonymous location information – the 95% number makes it highly highly suspect. I would love to see the link to the research. Please post.

    • It is listed in the “Sources” section at the bottom on the blog post. The research was published in Nature.