German politician, Malte Spitz's interactive life map through his mobile phone

Most people’s understanding of what can actually be done with the data provided by our mobile phones is theoretical; there were few real-world examples. That is why Malte Spitz from the German Green party decided to publish his own data collected from August 2009 to February 2010. However, to even access the information, he had to file a suit against telecommunications giant Deutsche Telekom.

The data, which ZEIT ONLINE has made available for download and acts as the basis for our accompanying interactive map, were contained in a massive Excel document. Each of the 35.831 rows of the spreadsheet represents an instance when Spitz’s mobile phone transferred information over a half-year period. Seen individually, the pieces of data are mostly inconsequential and harmless. But taken together, they provide what investigators call a profile – a clear picture of a person’s habits and preferences, and indeed, of his or her life.

This profile reveals when Spitz walked down the street, when he took a train, when he was in an airplane. It shows where he was in the cities he visited. It shows when he worked and when he slept, when he could be reached by phone and when was unavailable. It shows when he preferred to talk on his phone and when he preferred to send a text message. It shows which beer gardens he liked to visit in his free time.All in all, it reveals an entire life.

The law that the German Constitutional Court ruled unconstitutional on March 2, 2010, has been in place since 2008. It requires all telecommunications providers with more than 10.000 customers to save records of all calls and connections for six months. That means the entire communications record and all attempted efforts at communication via telephone, SMS, e-mail or internet are logged and preserved for half a year. Not the actual content, but all kinds of metadata that can reveal something about the type and nature of a contact.

To illustrate just how much detail from someone’s life can be mined from this stored data, ZEIT ONLINE has “augmented” Spitz’s information with records that anyone can access: the politician’s tweets and blog entries were added to the information on his movements. It is the kind of process that any good investigator would likely use to profile a person under observation. To prove how exact the data provided by his mobile phone is, his appointments are also shown as they were publicized on the Greens’ website. The locations revealed by mobile towers are mirrored there.