Please forgive my ignorance.
I understand (perhaps erroneously) that Snowden revealed, among other things, that phone calls are being recorded, and the data stored (if not actually listened to by a live human being), and flagged for various keywords.
I also understand that phone companies will give what data they have to investigators if given a warrant. But so far, in my reading of local news about various criminal investigations, I've never heard of actual phone call recordings used as evidence - only data about where the phone was at various times (pings off towers) and text messages, and phone numbers of in- and outgoing calls.
If this is all correct so far, I'm wondering why bother recording phone calls at all, if those recording are never used to incriminate anyone.
If the answer is simply 'because they can', or 'to scare us', then that satisfies my curiosity. I know better than to look for common sense on the part of the powers that be, in these things.