The guy who wrote the false wikipedia entry on John Seigenthaler has confessed. He wasn't a conspiracy nut, just someone who (he says) thought of wikipedia as a joke site.

This whole affair will have been good for wikipedia, I think. Readers will take articles with a grain of salt, and potential vandals will think twice before posting false information (the linked story of the noose slowly closing around the vandal's neck was satasfying to read and will probably provide good disincentives).