I just implemented a tentative anti-imposter system. It basically checks players with tags similar to ours against a list of member hashes. If the player isn't found on the list, he is kicked the moment he tries to join. The only problem with this is I'm not sure if the list I have is totally comprehensive. If you are a member and the server kicks you when you try to join with your tags on, please leave a reply so I can manually add your hash to the list.