From the NYRB:
Some articles are so out of the way that they get very little vandalism. (Although I once fixed a tiny page about a plant fungus, Colletotrichum trichellum, that infects English ivy; somebody before me had claimed that 40 percent of the humans who got it died.) Some articles are vandalized a lot. On January 11, 2008, the entire fascinating entry on the aardvark was replaced with “one ugly animal”; in February the aardvark was briefly described as a “medium-sized inflatable banana.” On December 7, 2007, somebody altered the long article on bedbugs so that it read like a horror movie:
Bedbugs are generally active only at dawn, with a peak attack period about an hour before dawn, though given the opportunity, they may attempt to feed at your brain at other times.
A few weeks later, somebody replaced everything with:
BED BUGS MOTHER FUCKER THEY GON GET YO MOTHA FUCKING ASS BRAAAAAAAT FOOL BRAAAAAAAAAAAAAAAP.