WHOIS search shows the information related to a domain registration (.GR, .COM, .EU, .NET etc.), meaning the owner information.
There are some restrictions regarding the domain WHOIS lookup:
1. For .GR domains, on WHOIS search results you see only the registrars name (e.g. papaki.gr) and not the owner's.
2. For .EU domains, on WHOIS search results you see both registrar's and owner's info, in case the registrant fills the field "Organisation" during the registration process. In any other case, the owner's email and the registrar's information is shown.
3. For .COM, .NET, .INFO etc. on WHOIS search results at Papaki, you can see the owner's email if he doesn't select to privately register his domain with the id protection service (ID protect). Learn more about ID protect;
You can search for a domain WHOIS information at http://www.papaki.gr/en/whois-search.htm.