What makes a jape great?

"Students at Yale scored a big victory during last year's football match against Harvard when they passed out pieces of paper to thousands of fans on the Harvard side of the stadium. The fans were told that, when held up, the bits would spell “Go Harvard”. In fact they spelled something else (see photo below)."

[If you can't make it out it says "We suck"]

Was this the greatest college prank ever devised? The Economist has some more suggestions here, and you can write in with your own.