whois dudoser.com/user/cubfarm75/

Domain:
Turn off cache
Try for webbased whois (don't expect it to work yet)

dudoser.com/user/cubfarm75/

checking....dudoser.com/user/cubfarm75/
$ whois dudoser.com/user/cubfarm75/
No whois server is known for this kind of object.