As I understand it, anyone can join as a non Pro and they aren't vetted at all.
This unfortunately means that the odd charlatan can appear for a while before being spotted. Generally they ARE spotted cos they either start ranting at someone as soon as they join, or shoot themselves in the foot by blatantly not being aware of the rules. Not much you can do about it really unless we have moderators on 24/7
It's true of an open forum, which is what MTvan seem to want, so this downside seems to be one they are prepared to put up with.
Thankfully most don't damage anything but there own reputation