On December 16, 2003, President George W. Bush signed the CAN-SPAM Act of 2003  into law.   CAN-SPAM derives from the bill’s full name: Controlling the Assault of Non-Solicited Pornography And Marketing Act of 2003.  The new law established the first national standards for sending commercial e-mail.  While it  doesn’t allow e-mail recipients to sue spammers or file class-action lawsuits, it does allows enforcement by the Federal Trade Commission (FTC), State Attorneys General, Internet service providers (ISP), and other federal agencies for special categories of spammers (such as banks). 

Senator John McCain is responsible for a last-minute amendment that makes businesses promoted in spam subject to FTC penalties if they knew or should have known that their business was being promoted by the use of spam.  This was designed to close a loophole for affiliate programs that allowed spammers to abuse their programs.  It also encourages them to assist the FTC in identifying spammers.