Domaintools.com is using data cached from WHOIS searches to domain name registrars, despite registrars providing this information on the condition that it is not repackaged or sold. The obvious privacy violation is probably also illegal, and Domaintools the site owner could be arrested and charged under the Data Protection laws of many countries if he goes abroad.
Domaintools.com, which was introduced in early October 2007, is a threat to privacy and safety, especially for the politically active and their families. Complaints have led to a discussion on the site, where the public can post at http://blog.domaintools.com/2007/11/registrant-search-is-it-right-or-wrong/#comments
There are reports that all activity on the site is logged and may be used later in unexpected ways, as the WHOIS search data has been.