When a troll needs terminating alerting Joe and Co is sufficient, and it'll get sorted out before very long. As appears to have happened in this case. A thread like this serves as a reward for the troll, though I'm sure it wasn't intended as that.

"...a serious weakness of this forum that anonymous GUEST messages are visible until such time as somebody gets round to deleting them implies that it should be impossible for anyone to post as a GUEST, which would be the only way to achieve that. I think we'd collectively lose more by that than we'd gain.