according to a search on google you can discover the owner of a private domain by asking the registrar and giving a reason, i haven't done it myself so cannot vouch for the authenticity of the information
I hear what you are saying but if you look at the websites of registrars they say that some people run sites that requires their identity to be protected or their lives could be in danger. And private registration will protect you from those dangers. I think this could be true sometimes. So would giving the registrar a reason for asking about who owns a domain be something that works?