CAN-SPAM Act of 2003 - 15 U.S. Code sections 7701-7713
The Controlling the Assault of Non-Solicited Pornography and Marketing Act requires unsolicited commercial e-mail messages to be labeled (though not by a standard method) and to include opt-out instructions and the sender's physical address. It prohibits the use of deceptive subject lines and false headers in such messages. The FTC is authorized (but not required) to establish a "do-not-email" registry. The CAN-SPAM Act took effect on January 1, 2004.
Telephone Consumer Protection Act (TCPA) - 47 U.S. Code section 227
This law puts restrictions on telemarketing calls and on the use of autodialers, prerecorded messages, and fax machines to send unsolicited advertisements.