In the news media I keep on seeing/hearing the phrase "Wire Tapping" in the
context of the current issue about NSA doing same without warrants  - as if some
guys were plugging into people's phone lines and recording the conversation as
on a recent cover of "The Week" mag.

Doesn't make sense to me.

First, if they knew in advance who was calling who they'd just get a FISA
warrant within the 72-hour period and avoid controversy.

I think it's more like they don't know in advance who they want to listen to and
they want to troll for suspicious conversations - not knowing in advance who is
talking to who.

To make it realistic in term of man hours spent I'd think they'd be running
thousands of phone conversations through some sort of keyword-sensitive software
and then flagging the "interesting" ones for human intervention.

If that's the case, it would seem like the logical corollary of that is that
*all* potentially-interesting phone conversations exist in their entirety on
some sort of digital media for some time period - to allow the high-volume
automated review - the question being what the bounds of "interesting" are.

Anybody actually know how it's done?