Comments:

The problem with a registry is that marketers ignore it, and proceed with mailing (or phoning), because there is not enough penalty. Moreover, there is software constantly being developed that enables people to hack, or comandeer computers and/or databases and servers where their mass mailings are sent from other computers, thus leaving them unsoiled and undetectable. There needs to be more accountability at the server and ISP levels, and real teeth in the laws that encourage reporting and serve financial punishment to those who persist in spamming. I receive countless emails that 'appear' to be benign email from a friend but turn out to be commercial ads when opened. Another issue is that many companies are utilizing off-shore servers and companies to send their bulk mailings.