The WHOIS domain database is a listing of all registered domains, and is regularly used for various legal purposes. Network administrators use the WHOIS lookup to identify and fix problems. For instance, WHOIS information can be used to check domain name availability, identify trademark infringement, and keep domain name registrants accountable.
WHOIS verification can even be utilized to combat spam or fraud, as administrators can track down registrants who post illegal content or participate in phishing scams. In addition, the agreements from the International Corporation for Assigned Names and Numbers (ICANN) protects domain registrants by prohibiting the use of WHOIS listings for marketing or spam purposes, including high-volume, automated queries against a specific registrar or registry system (unless such queries are done with the intent to manage domain names).