Your cell phone company knows where you are, twenty-four hours a day.
Malte Sptiz did an experiment and requested all data that T-Mobile had collected about him over the last 6 months. It took some legal effort but he did manage to receive a spreadsheet with 35 thousand entries describing his every move. He sent the data to a newspaper “Die Zeit” which reconstructed Sptiz whereabouts over the last 6 months. The data is pretty extensive one can see where he walked, took the train or grabbed a beer. Check the interactive map that “Die Zeit” created to convince yourself how much data is gathered just by tracking your mobile phone.