Whois

The original purpose of the WHOIS database was to provide a directory for domain owners, the publicly available information opened the doors to mass spam and other abuses. The terms and conditions of WHOIS databases include a provision that the information revealed shall not be used for such purposes, but this has proven to be a rather anemic solution.
To further discourage data miners, most WHOIS sites have implemented a script with a random graphic display of numbers or letters which the requester has to manually enter into a field. "Bots" or data scouring programs cannot read these graphic displays, disabling results from automated queries. Beyond precautions such as these, there is no real mechanism in place to catch, identify, or punish abusers of WHOIS information.