Let’s say you want to send a package to my personal trainer, Alison. If you know two facts about me, you can have the package delivered for free. Fact 1: the local dairy delivers milk to my front door very early each Thursday morning. Fact 2: I see Alison every Thursday morning (after the milk is delivered).
So, if you could get the package to the dairy, the milkman could deliver it with my weekly supplies (without going out of his way). I could pick up the package (without going out of my way) and deliver it to Alison. Everybody is happy, nobody has gone beyond his or her normal routines, and the package is delivered quickly, efficiently, and cheaply.
How would you know those two facts about me? By following my Twitter feed. Yep, Twitter. By analyzing where my Twitter feeds come from, a system could conceivably track my whereabouts and predict where I might be at a given time. Theoretically, it could do this for thousands of people and plot an efficient series of hand-offs from one person to another. (I probably don’t tweet enough for this to work, but lots of people do).
The concept is known as TwedEx. It’s not here yet but it might soon be – you can read more about it here.
Here’s the creepy part, in my opinion. If a system can predict my movements based on my tweets, what can the government figure out based on the PRISM program?