Frequently, WHOIS searches on existing domain names are leading us to dead ends because of the proliferation of private domain name registrations such as those offered by Domains by Proxy and the Network Solutions private domain name service.  A subpoena to the registrar often triggers a private notice to the true domain owner allowing them time to attempt to quash the subpoena or move on to a new domain.  One potential end-run to this problem may be to file a complaint against the private registration service directly.  Assuming that there is a good faith claim, a direct suit can often result in the registration service using their contractual right to reveal the registrant, typically to avoid liability.  When a UDRP complaint is filed, for example, the private registration service may attempt to modify the WHOIS entry with the hidden contact information prior to the commencement of the proceeding.