Harbinger of doom, or just reality as it exists now?

This afternoon one of the college students who have recently been promoted from page to adult clerk was making phone calls regarding a program at the library. She turned to me at one point and said, "What does it mean when you dial the number and it just goes 'beep, beep, beep, beep'?"

"You see, back in the dinosaur times, people did not have voicemail, call waiting, and automatic forwarding systems. If you called someone while they were on the phone with someone else, you got what you just heard, a Busy Signal." I told her I would remember this moment forever, because it was proof how much life had changed regarding the telephone. She had never heard a busy signal before!