I've called it a myth because that exactly what I think it is. Yet I see it being mentioned from time to time on here. Im not talking about problems arising from having whois protection on all your PBN sites - thats obviously a footprint problem. What I mean is people saying you need to use different emails when registering a domain using whois protection like whoisguard. From the whoisguard terms Which backs up how I understood it works. Whoisguard are owned by Namecheap. Namecheap is the registrar. So the domain's whois is registered to whoisguard. Whoisguard's backend on their servers handles the forwarding of the domains contact emails to your email. At no time is your email or address even entered into the whois database. For that reason its not simply a case of other registrars (like google) being able to "see though" your protected whois details. In fact the only time your real details would appear is if you have the domain live without whoisguard first. In that case they would be public and whois.domaintools etc etc would all see your historical info. The only way they can get the domain details is by requesting it off whoisguard as it is them that have the data storage agreements with you as the domain owner. Now, as for how easily whoisguard will release your details if someone asks them that's anyones I guess but I tried doing a copyright claim through whoisguard and got nowhere with it. They list all the obvious reasons in their T&C but gaming search engines is not in there unless you can claim its hacking related. So that leaves the possibility that google and whoisguard have some sort of back room agreement where google gets slipped confidential information on domain holders at their request (and in bulk!). Unlikely as both these companies are covered by various data protection acts that prohibits that kind of activity unless its in the T&C's. Thats my view anyway. Im always looking to be educated though so I'd love to hear the views of anyone more experienced with this? tl;dr? Yes, you can use the same email when registering multiple domains that have whoisguard protection. No, you shouldnt use whois protection on your whole PBN!