There are other writeups here which have the details, but
here's the story behind it all...
Back in 1996, Al Gore was invited to be the Commencement speaker at the Massachusetts Institute of
Technology. Up until the 1980's, the Commencement speaker had usually been the President of the Institute, and although the speakers had been getting more prestigious as the years went on, it was generally assumed that the Vice President of the United States was the most impressive personage we were going to host. The hackers
therefore decided that a correspondingly impressive hack was necessary, in the long tradition of Commencement hacks.
The original idea was to drop a banner down reading "The MIT Assassins' Guild welcomes President Gore", but
that was quickly vetoed by the Couth Committee. For one thing, the Secret Service would take apart the Institute brick by brick looking for the assassination plot; for another, the usually peaceful members of the Assassins' Guild would break their normal rules against killing for the people who pulled that particular hack. So they thought some more.
Now, most of you have heard about how Al Gore invented the Internet. At the time, Gore had a reputation for using buzzwords constantly, most of which he didn't understand. So the hackers created bingo boards with varying buzzwords in the squares,
with rules directing players to cross off squares when they heard Gore use the buzzword in his speech. These boards and instructions were placed on every seat in Killian before Commencement.
Gore, however, was more clever than the hackers had given him credit for. He figured out that when giving a speech at the nation's premiere technological university, the listeners probably knew more about technology than he did, and he used almost no buzzwords in his speech. Apparently, someone had tipped him off to the hack as well; at one point during the speech, the Architecture majors burst out laughing from some inside joke and Gore asked "Did I say a buzzword?"
Nobody actually won at bingo that year, which was probably all for the better. When President Clinton showed up for his Commencement address a few years later, however, he didn't follow Gore's lead. Rumor has it that anyone playing Buzzword Bingo that year would have actually won.