Welcome to WebmasterWorld Guest from 188.8.131.52
Forum Moderators: bakedjake
The default whois will display your registration details.
It's up to you to arrange anonymity with your registrar.
Alexa is simply repeating what is already public knowledge - same as they do for every other non-anon site. Believe me, Alexa never had an original thought, and all their info is automated.
Go check your registrar's terms. Mine does it for free, some charge a fee.