I personally assume that they're collecting everything, but analyzing very little. Just a quick grep on some key terms for some communications of interest, for some possibly very odd value of "interest".
They can always go back and analyze later.
Old-time "usenet" users have to assume that all of usenet got hoovered up while it was going on, and that material is pretty carefully indexed and categorized. Any participants of "alt.tasteless", for example, should never run for major office, as whatever they posted will come back to haunt them. By "haunt them", I mean that once elected, they may get their arms twisted on critical issues. Let's recall what happened to Representative Jane Harman (http://www.thedailyshow.com/watch/tue-april-28-2009/your-gov...) - Harman "was caught on wiretap, but not punished, so as not to erode her support for wiretaps."
That guy that posted all that gay pr0n to the straight-pr0n groups in the early 90s had better watch his back, too.
Yeah, you run into a fundamental noise:signal issue.
The idea is probably there is a small subset that is analysed pretty heavily and a lot else that's just retained on the theory it might be of interest someday.
The danger though is it allows a bit of a "show me the man and I'll find you the crime" mentality....
Well, we know about Jane Harman, and we know about J. Edgar Hoover's files on just about all USA Congress members. I believe your "danger" is an actual problem. That sort of thing really undermines representative government.
It is the actual problem. It is what is supposed to separate a government of laws from a government of men. Indeed, the quote came from Stalin's government....
They can always go back and analyze later.
Old-time "usenet" users have to assume that all of usenet got hoovered up while it was going on, and that material is pretty carefully indexed and categorized. Any participants of "alt.tasteless", for example, should never run for major office, as whatever they posted will come back to haunt them. By "haunt them", I mean that once elected, they may get their arms twisted on critical issues. Let's recall what happened to Representative Jane Harman (http://www.thedailyshow.com/watch/tue-april-28-2009/your-gov...) - Harman "was caught on wiretap, but not punished, so as not to erode her support for wiretaps."
That guy that posted all that gay pr0n to the straight-pr0n groups in the early 90s had better watch his back, too.