Access to Members List

Today while running thru some other issues I discovered that unregistered guests have access to my members lists and all of the user profile information. Can someone please help me to turn off this information so that I can protect my members. I've tried to go to the vb.com site but it would appear that I'm part of that IP ban so have to wait for them to give me access back to that site.

I noticed that on this site if someone hasn't logged in them they get a message about the member not being be part of a public forum if their profile information is clicked on - how the heck do I do that???

(oh and obviously I'm a novice at this stuff - thank you so much!!!)