Interesting article here:
What Does Your Phone Know About You? More Than You Think - Alexis Madrigal - Technology - The Atlantic
I plugged my phone into my computer and opened an application called Lantern, a forensics program for investigating iPhones and iPads. Ten minutes later, I'm staring at everything my iPhone knows about me. About 14,000 text messages, 1,350 words in my personal dictionary, 1,450 Facebook contacts, tens of thousands of locations pings, every website I've ever visited, what locations I've mapped, my emails going back a month, my photos with geolocation data attached and how many times I checked my email on March 24 or any day for that matter. Want to reconstruct a night? Lantern has a time line that combines all my communications and photos in one neat interface. While most of it is invisible during normal operations, there is a record of every single thing I've done with this phone, which also happens to form a pretty good record of my life.