By filing a legal suit against Deutsche Telekom German politician Malte Spitz (Green party) was able to obtain data recorded under the German preventive data retention act. He chose to publish the data which was collected in the timespan from August 2009 to February 2010 and encompassed exactly 35.831 individual records (Spitz’s phone checked for new mail every 10 minutes when it was switched on – which it was 78% of the total time). German Newspaper Die Zeit claims there is big (geo)profiling potential in such a data set. To prove the point they combined the telecommunication data with publicly accessible data such as Spitz’s tweets, blog posts and scheduled meetings as listed on the politician’s website and turned it into an animated visualization in collaboration with Berlin-based company OpenDataCity.
It’s indeed frightening what information can be gained by mashing the cellphone (a.k.a. tracking device) information recorded by a phone provider together with publicly accessible data on social media platforms and websites. And the analysis by Die Zeit hasn’t even used the most private information, namely whom Spitz called and who called him on his cell…
Some more background information is available on the Die Zeit website (thankfully by now also in English, I guess they figured the topic might be interesting to many).