Here’s a pretty extreme example of public/private data cooperation.
The Visible Man: An FBI Target Puts His Whole Life Online
There are already tons of pictures there. Elahi will post about a hundred today — the rooms he sat in, the food he ate, the coffees he ordered. Poke around his site and you’ll find more than 20,000 images stretching back three years. Elahi has documented nearly every waking hour of his life during that time. He posts copies of every debit card transaction, so you can see what he bought, where, and when. A GPS device in his pocket reports his real-time physical location on a map.