Deutsche Telekom’s dataset already kept one part of Spitz’s data record private, namely, whom he called and who called him. That kind of information could not only infringe on the privacy of many other people in his life, it would also, even if the numbers were encrypted, reveal much too much about Spitz (but government agents in the real world would have access to this information).

While data retention allows for the creation of a profile of an individual’s movements, it also paints a picture of a person’s relationships. The data reveal who is a friend and who is family. The information shines light on clandestine connections as well as illicit love affairs.

Spitz is a politician, and as a member of the Greens’ leadership council he’s on the road a lot. While this means he is not an average citizen in some ways, his frequent use of his mobile phone – making calls, texting and surfing the internet – is decidedly mainstream for many these days. 

Every ten minutes, Spitz’s phone checked in with his provider to see if there were new e-mails, a function that many smart-phone owners have activated. Since his phone was rarely turned off, Spitz’s movements were tracked 78 percent of the time.

Six months – that’s how long many German politicians want data on calls and e-mail exchanges to be retained and it’s the same amount of time Spitz made himself available. Such a period would clearly suffice for investigators to be sure a person had no more secrets. Indeed, as long as a mobile telephone is turned on, the activities of its owner are being broadcast. And even if a phone isn’t on all the time, there can still be enough information available to create an accurate profile.

Thirty years ago, Kraftwerk’s line "Flensburg and the BKA" described a world where personal data had slipped out of our control and into the hands of big government agencies. Today, that lyric would have to be changed to: Telekom and the BKA, they’ve got all our data squirreled away.