The domain has private registration, but at least it uses DomainsByProxy. If you visit the whois:
Whois Lookup | Domain Availability – Registration Information
And send an email to the domainsbyproxy email it will get forwarded to the registrant email. Not sure of exactly which other privacy protection services offer this, but I know for a fact GoDaddy’s does. Then all you have to do is hope the owner of that domain checks whatever email he has set for the registrant email 