Back in the day, Dragon magazine used to have a section where readers sent in their letters- questions, stories, whatnot. One reader sent a letter imploring Dragon to create some more challenges for him, as his uber-level wizard named Waldorf had destroyed all the villains Dungeons & Dragons (I seem to recall him being tied specifically to Greyhawk- either having destroyed it or taking it over).
Well, that set off a chain of letter writing in which people sent in their uber-characters, trying to outpower Waldorf, whose creator responded in kind. It went on for several issues before the Dragon staff finally put an end to it. It was pretty funny, especially not knowing who was really being serious or not.
Dangit- now you're going to make me go dig out all those Dragon issues to remind me exactly what went on.