I don't really like that chat system actually. Everybody seeing everything that's happened before is a little breach of privacy imo. Doesn't give a very casual feeling from the start. Who knows somebody likes to discuss reallife matters, foods, games and so on, do we need to see all of them if we weren't part of discussion? Also i've been in numerous IRC chats, and never seen a single spammer. I don't really know where your experiences with them base on.