>> Roughly the same way you sort through massive amounts of geophone data to determine where on earth to drill for oil.
You’re talking about static data.
There’s no way one person can continuously receive, process, and analyze an aggregate of all the data being processed in every central office, mail server, regional routers, etc. It’s a fantasy to think that’s possible.
The NSA uses continuous indexing to find associations between things. However, a person can also query all that data and ask for specific things. Of course no person can sort through much data at all by themselves. Often queries take days or weeks to perform as all queries are queued according to priority.
Wow. Just wow.