Remember the days before caller ID, when we generally had no clue of who was on the other end unless we recognized the voice or the other person introduced him/her/self?
I can remember a couple of thriller movies based on the idea of a frantic search for the location of the phone booth where a man with a bomb was about to blow up a chunk of the city. Typically, it involved detectives racing through the banks of a phone company building trying to narrow the search to a two-block area.