whois dudoser.com/user/pvchoe4/

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

dudoser.com/user/pvchoe4/

checking....dudoser.com/user/pvchoe4/
$ whois dudoser.com/user/pvchoe4/
No whois server is known for this kind of object.