What happened in 1971? I’m only 26.
The short version is that on Feb. 20th, 1971, an operator who worked at NORAD named W. S. Eberhardt loaded a tape into the teletype transmitting system to be sent out for the usual Saturday morning test. Problem is, it wasn’t the test tape...it was an actual attack warning, with the proper authentication codes and everything. It went out to everyone who had an Associated Press or United Press International teletype machine.
A bunch of stations did as they were supposed to and went off the air. Another bunch of stations tried to verify the message, some ignored the message entirely, and some didn’t even GET the message. To make matters worse, even though all stations were supposed to have the authenticator words in envelopes in the studio, some opened their envelopes and found nothing at all.
It was an embarrassment for NORAD, but a giant failure for the EBS system. They made some changes, but didn’t re-vamp the system until the advent of the EAS a few years ago.
To read an eyewitness account, do a search for “The Great EBS Goof of 1971”.