Via Things Magazine, sometimes, behind everything lies confusion:
The False Alarm of 1971 was an accidental triggering of the USA-wide Emergency Broadcast System, ‘an expeditious method of communicating with the American public in the event of war, threat of war, or grave national crisis.’ A detailed description of the event is chronicled here, the great accidental test broadcast of 1971, complete with a scan of one of the most ominous documents to ever be received by a Teletype machine:
THIS IS AN EMERGENCY ACTION NOTIFICATION (EAN) DIRECTED BY THE PRESIDENT. NORMAL BROADCASTING WILL CEASE IMMEDIATELY. ALL STATIONS WILL BROADCAST EAN MESSAGE ONE PRECEDED BY THE ATTENTION SIGNAL, PER FCC RULES.
The fault originated from the heart of Cheyenne Mountain in Colorado and involved the accidental inclusion of a real code word – ‘hatefulness’ – on a test transmission of the Emergency Broadcast System. As one broadcaster reportedly said, “This confusion ‘shows the whole darn (system) won’t work. They could’ve been dropping H-Bombs on us.’”