The problem is that connections like these occur purely by chance. When you multiply the events together you get a low probability ... but there are hundreds of millions of Americans. There will be a lot of false positives.

And how will they be treated? It seems: poorly.

I'm personally more frightened about someone like the IRS being handed data from the NSA, than the NSA thinking I'm a terrorist, and I pay my taxes and everything. I'm just frightened about being nailed for any tiny mistakes that I have made in the past, that this data capture could glean, if that makes sense?

FWIW, I'm not even from or in the US of A, but I'm worried about my government doing something exactly like that considering how much it's cooperated with the NSA directly in the past and present.

ah, but it's plausible cperciva is connected to a suspected terrorist and might be using the magazine stand in the dentists waiting room for dead drops..