It's not as though the NSA hasn't been listening to Americans' international phone calls for a long time.
I just finished buying a car, and just about every salesman I dealt with was ex-military. One of them, trying to warm up, got to talking about his rotation out at the NSA. He recounted in some detail a conversation between an overseas soldier and his stateside wife, and then how they left the circuit open, and heard the wife invite her boyfriend over.
This was, I note, a couple of days before the Times printed the details of the currently-controversial program.