Actually, there’s one filter, and it’s ridiculous: an NSA analyst has to have “51 percent” confidence that a subject is “foreign.” After that, it’s carte blanche.
Gizmodo has a great overview of all the ins and outs of how the government can and does snatch and grab ALL OF OUR personal online information through a little program called PRISM. I’m sure this filter of theirs must work wonders though. Nevermind that I can find metadata about anything through the simple tools I use on the web. Man, I must be some kind of genius.
go read (Touch Me!)