A big new step in website owner privacy is starting this week. ICANN has agreed to remove phone numbers from all WHOIS details. It’s well known these listed phone numbers get spammed out real quick! And they are never used for anything relevant to the domain name. Of course ICANN wanted as much information from the domain owner as possible since they collect data as well.
Forced by the top domain registers around the world, ICANN has agreed that having a phone number with WHOIS is not needed and will be removed permanently on all WHOIS searches.
The transition will take some time, and certain domain registers can block it for the time being. I think a domain register would only block removing phone numbers if they were already using the phone numbers for their own back-end marketing systems. That makes this a good experiment to find out what registers were actually using your WHOIS data for marketing purposes.