The Best of Sloganator
Back in March 2004, the Bush campaign website introduced a handy service for people who visited the site: The Sloganator, featuring a graphic of the standard Bush/Cheney campaign logo with a nice aesthetic blue space at the top of the graphic. Visitors could enter a slogan to appear in that blue space, and use the result to print their own campaign posters.
What they failed to remember was that the people who visited the Bush site weren't necessarily Bush supporters. In short order, the Sloganator had to be re-programmed to reject slogans including words that aren't supposed to be used in public. And after a few weeks, the Sloganator was removed entirely, because too many of the people using it were having wayyyyy too much fun.
But the Web has a long memory, and if you click on this link, you'll see a slideshow of some of the best of the *ahem* irreverent Sloganator entries.