He didn't get banned from the conference. He got banned from Rick's forum.
I wasn't accepted there cause someone who is also a member here said I did him wrong. I have send him numerous PM's and emails but he remembers no details of what happened years ago. He just thinks I asked him to register a few domains for me but he is TOO busy to search his emails. Well, I haven't asked ANYONE to register domains on my behalf, let alone him, that I don't know at all.
So you can see it is pretty easy to get banned from a conference.