A company (CompanyX) exist that makes millions of $$$ with their web portal business. And has quite a number of domain names.
Let's say, they own this fictitious domain:
MainNiche.com
Their business runs several successful sites that are part of the main niche they are in but are more specific and runs on their own separate domains, for example like:
MainNicheSubNiche1.com
MainNicheSubNiche2.com
MainNicheSubNiche3.com
Now, a totally different random person (PersonY) owns a domain MainNicheSubNicheN.com has fake whois info (Even uses my mailing address!) and did not run a private registration whois, registered the domain name through my domain registration business. (I am not an ICANN accredited registrar. I am just a reseller with it's own API/turnkey solution thing.)
Now CompanyX has been contacting me stating that they will take some action to get the domain which they claim they have a trademark for.
And being not the owner, I just pass the message to PersonY which acknowledges the email I sent but does not take any action in fixing the issue.
CompanyX keeps telling me they will take some "other actions" to get the domain and I do not own the domain anyway. Why tell me? But I also do not want to give the ownership details of the domain since I may be in violation of my own Privacy Policy that PersonY might get back to me with. Now what I am not sure of is up to what extent do I suppress from giving out the private info? And who knows CompanyX can charge me for being part of PersonY's plans even if I am not really a part of it since I am just the domain name registration company.
I am not used to situations like this and I do not know what is best to do.
First, you should contact a lawyer, and have them explain the potential legal issues surrounding your business to you. You should already know the answer to your question. But it's never to late to do the right thing.
While you are there (at the lawyer's office) explain the current situation and seek their advice.
Whatever else he tells you, he's likely to tell you that you shouldn't give out private registration details without a court order or service of discovery.