An Oklahoma-based anti-spam crusader who sued over repeated cruise vacation e-mail ads has put wind in the sails of spammers with the first federal appellate court ruling limiting the reach of state laws that restrict unwanted e-mail.

The 4th U.S. Circuit Court of Appeals held that a 2003 federal law, known as the CAN-SPAM Act, pre-empts state laws that allow suits for false information in junk e-mails if the misrepresentation is “immaterial.”