I use StatCounter to track the visits to a few of my Web sites. Lately I have discovered a number of visitors that are logged as coming from Private IP Space addresses (, etc.).
I know what’s happening here. These folks are behind proxy servers. When they request the StatCounter object, it is actually requested from the proxy server, which then logs their Private IP address, not the one on the external interface of their proxy server.
I also examine my Apache logs and can easily correlate these visitors to their external IP addresses.
A weird “feature”, but kind of cool, except if you are the security admin for these networks.