If you have an Android or Ios smartphone, it defaults to storing the history of all the places you go, at a very fine resolution, for a very long time, and mirrors that data on remote servers from which it might be leaked or subpoenaed. Lifehacker has a great tutorial on deleting your Location History and turning off future logging of your location. They cover both Ios and Android. I just did my devices, and it was very easy.
To disable location reporting or history in Android:
* Open the App Drawer and go to Settings.
* Scroll down and tap Location.
* Scroll down and tap Google Location Settings.
* Tap Location Reporting and Location History, and switch the slider to off for each one.
* To delete your phone's location cache, tap "Delete Location History" at the bottom of the screen under Location History.
* Repeat this process for each Google Account you have on your Android device.
I write books. My latest is a YA science fiction novel called Homeland (it's the sequel to Little Brother). More books: Rapture of the Nerds (a novel, with Charlie Stross); With a Little Help (short stories); and The Great Big Beautiful Tomorrow (novella and nonfic). I speak all over the place and I tweet and tumble, too.