The Great Rose Bowl Hoax of 1961:
http://www.museumofhoaxes.com/pranks/rosebowl.htmlNerds from CalTech hack the University of Washington's Rose Bowl card stunt.
The first eleven images of the flip-card show had been left basically unaltered, to allay suspicion. The first real alteration occurred with the 12th image, which had been changed from a husky to a beaver, Caltech's mascot. This change was subtle enough that it escaped the attention of most of the game's audience. The 13th image had been flipped so that it read 'SEIKSUH' instead of 'HUSKIES'. The Fiendish Fourteen knew that viewers would chalk this up to simple error. But these changes were a mere build-up to the 14th image, the unveiling of 'CALTECH' itself.
At the moment when Caltech's name unfurled across the stadium, NBC's cameras were focused directly on the flip-card show, providing the best possible vantage point for viewers across the nation to watch the ensuing drama. Washington's band, upon seeing the gigantic rogue name leering down at them from the stands, immediately stopped playing, and silence descended on the stadium. Even the television announcers were momentarily speechless. For a few seconds this silent tension enveloped the entire stadium. Finally the significance of what had just happened began to sink in, and then the laughter began.