Are there any restrictions on the type of phone number I can give as my WHOIS contact? Notwithstanding that it is a phone number which can be used to contact the domain holder.
For example, what if I change it to a premium rate line? If the scammers want to talk to me so much, make them pay for the privilege!
In the UK, cell phones are more expensive for the caller to call than land-lines, so I suspect a significant number of people are already listing a "premium rate" phone number.
EDIT: Many thanks to Chloe and Eduardo for their links to WHOIS privacy services, but I'm really interested in an answer to my question. The idea of someone using a premium rate phone number was to set the scene for the most extreme example of a phone number that defeats the purpose of having a phone number published in the first place.