When you register a domain name, the Internet Corporation for Assigned Names and Numbers (ICANN) requires your domain name registrar to submit your personal contact information to the WHOIS database. Once your listing appears in this online directory, it is publicly available to anyone who chooses to check domain names using the WHOIS search tool.
There are a variety of third parties who may check domain names in the WHOIS database, including:
> Individuals check domain names for expiration dates
>Registrars check domain names when transferring ownership
> Authorities check domain names when investigating criminal activity