“A favorite pastime of Internet users is to share their location: services like Google Latitude can inform friends when you are nearby; another, Foursquare, has turned reporting these updates into a game.

But as a German Green party politician, Malte Spitz, recently learned, we are already continually being tracked whether we volunteer to be or not. Cellphone companies do not typically divulge how much information they collect, so Mr. Spitz went to court to find out exactly what his cellphone company, Deutsche Telekom, knew about his whereabouts.”

From The New York Times