I clicked it, and got nothing.
Security Questions: When the chat is going, can you see everyone who is watching? Will only registered members be able to see it? When people sign in, will anything that was posted before they signed in be visible?
What browser do you use? Its a Java applet and requires Java to be enabled.
When you are in the chat, you can indeed see everybody who lurkes. This is valid for both the applett and Chatzilla, which I prefer.
The chat applett is only avalable for registered users, but its an irc-chat, so anybody who knows how to operate that can come in.
If you do not like that, it's possible to convert it to an invite-only channel, but that somehow defeats the purpose to be open to all
users.
And no, when you enter the channel, you only see what comes then. It is easy check the IP of any newcomers, but they also can see
your IP.