Every website and forums can look and see what a users IP is. A website admin can also see what site you were at before you navigated to grasscity, just not what user was on that site. So if you were on google.com before you came here, there would be a hit on that site to the GC, but only sites that you were on when you navigated to GC.
Or rather, there would be a record on THIS site of where you navigated FROM; i.e. Google. It's called a "referer". If you came straight here, there is no referer. But we still haven't answered the question, and I'm not in a position to. -mu