The forum thread Chat bot for SecondLife gives a 404:
http://www.chatbots.org/ai_zone/viewthread/314/
The reason is because the author of the topic no long exists, so ExpressionEngine does not return the results.
In other places EE does link to it, see for instance link at bottom of this page:
http://www.chatbots.org/ai_zone/viewthread/308/