The original comic featured a made-up word made up of words that dealt with making up words (with the original words, ostensibly, disproportionately popular on Wikipedia). Don’t be ashamed if that seems tough to follow – any web comic that has an explanatory blog is pretty high-end stuff to begin with. What isn’t tough to follow is that some enterprising fans created a Wikipedia entry for the made up word.
The ensuing debate among Wikipedia users and site editors took 19,000 words and resulted in searches for the word (“malamanteau”) redirecting to XKCD’s own Wikipedia entry. But it illustrates a good cautionary tale for user-generated content: it’s best to have good site rules up in advance in case you want to maintain any semblance of message control down the line.
And it’s also good to keep an eye on Wikipedia. Anyone can edit it, including people who might not have good things to say about you.