That thing in your pocket can talk, and it tells the tale of your life.
Mobile phone companies have data on your use of your mobile phone — where you were when you used it, whether you texted or spoke to someone, whom you called, and how long you spoke — and when those data are assembled and analysed a remarkably clear picture of your life emerges.
German politician Malte Spitz, a member of the Green Party, is concerned about phone company data retention, a hot topic in Germany now as the government is about to decide on new rules governing this. Spitz sued Deutsche Telekom to obtain the data about his own phone use between August 2009 and February 2010, then German newspaper Zeit Online coupled the huge spreadsheet of phone use data with available internet data about Spitz's talks etc. to produce an interactive map of Spitz's life.
As the story in Zeit Online puts it:
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.