Wire taps are a thing. I don't know the law around it, but it likely requires approval from a court. https://en.wikipedia.org/wiki/Wiretapping#United_States ht

Wire taps are a thing. I don't know the law around it, but it likely requires approval from a court. https://en.wikipedia.org/wiki/Wiretapping#United_States https://en.wikipedia.org/wiki/Wiretapping#United_States Otherwise, telecom companies keep records of all calls that take place on their network - the phone numbers, time, duration, etc.