True.
However,
They reportedly have very sophisticated software to evaluate on when to ping a human overseer.
Whether that involves combinations of keywords, context, sources, topic used within, or more likely any and all of the above . . . is not specifically understood by those outside the system, imho.
BTW, total monitoring of all electricity based communications channels by literally acres of computers has been going on AT LEAST for 40 years.
NO doubt.
I wonder if this is a keyword: VPN