You don't show on anonymous users if you choose to be invisible. You show up on the registered user total count. So there might be 37 registered users online, but only 25 listed. Anonymous users are those who have not registered, (or registered users who are browsing without logging in)
I'm the 11th down on the anonymous list, I think, did we not have a discourse on this a few months back, if you are logged on you and your details appear on search engines.
Nothing to do with logging on - just whether you have filled in profile details or not. The web search spiders will search and cache all profiles .... whether you are logged in or not
I often will show as 'anonymous' and the reason for that is that I sometimes just want a quick look to see if there is any thread of interest and over a dial-up, for we don't all have broadband yet, the log-in is just another time consuming step. Only if there is a thread that I want to respond to will I bother to log-in.
What's to get upset about this? think of it as listening to a conversation rather than talking. Maybe we just don't feel we have anything to say.