Your computer may be infested with spyware

Some software on your PC is trying to promote a third-party Web site in the Referer field.
This can be done by a browser, browser add-on or toolbar, download accellerator, firewall, anonymizer, file sharing software, etc.

Please uninstall this software.

If you want anonymity, leave the Referer field empty. Do not fill it with crap that I have to look at when reviewing my server logs.