While "anyone can post as anyone" to Usenet, there is absolutely no reasonable doubt that the material quoted as Boyd was really written by Boyd.  Ten years later, Boyd has never denied it.  If he really didn't write that, why wouldn't he have said "I didn't write this" rather than delete the quotes?  There are literally thousands of poker players who can verify receiving numerous emails from Boyd saying "Your check is in the mail," "Don't worry, you WILL be paid" and the like.  And if you personally really believed this material wasn't written by Boyd, you would have said something during the 2006 discussion when you actually approved of its inclusion at the time.  That "another person editing disagrees" isn't relevant, and it's clear there are lots of agendas involved, i.e. the user who initially removed this info is clearly Boyd because the username is the same as his livejournal, and the IP address that removed it later is probably him as well (since the edit also included "Boyd is appealing the decision."