sannse wrote in part:
Jimbo said: "This is a true simple vandal with a track record. He's banned from wikipedia, and that's that. We must not encourage him by considering each of his edits independently. Anything he writes should be reverted instantly, and his username vaporized as fast as possible."
When a persistent vandal is making several fast edits, we can't expect people to review each one to see if it's vandalism, so I think that it's quite reasonable to revert with prejudice. OTOH, if an ordinary, unbanned user comes along and says "Unlike the others, this one happens to be a useful contribution, and I WILL TAKE RESPONSIBILITY FOR IT as if I'd written it myself.", then there's no need to revert it just because of who first wrote it. Such an arrangement should probably be documented on the talk page, or we could even do a reversion and let the other user unrevert under their own name (or IP address).
-- Toby