[observationist]

If you know the suspect purchased a bag of funyuns, pack of marlboro lights, and a diet dr. pepper 1 liter, having the shopping history of every 7-11 customer for the last X years could give you a high probability of identifying exactly which customer it was, or eliminating exactly which customers it wasn't, from a list you compile from a large set of information sources.

Using metadata and tracked information of known individuals can illuminate the lives of people who aren't tracked through process of elimination and correlation, which is why privacy rights are so crucial to legislate correctly. Right now, the US justice system is not at all equipped to properly handle the scale and scope of private industry's panopticon providing more or less total global surveillance.

We need to see some legislation with teeth, big and sharp enough to completely kill any business, no matter how large, if privacy isn't respected. But hey, let's all enjoy being tracked, logged, monitored, and surveilled every second of every day in the meantime.