Ron knows, usually right away. I would say if you think someone that has been banned is posting under a different name, trying to get around the ban, email him with your thoughts, and have some information, not just a guess kind of a thing. and? yeah lots of members have more than one name, I wouldn't feel stupid for welcoming them. Sometimes they use different names to try out different styles of poetry, or maybe to post something they don't want people to know that "X" posted something like that, or maybe to be able to post something in mature, without worrying about freaking anyone out.
hope that helps.