Under the Junk Fax Prevention Act of 2005, the sender of an unsolicited advertisement sent to a person's fax machine is still liable for a minimum of $500 per page, and damages may also be trebled at the court's discretion upon a finding that the violation was willful or knowing.
The statute is one of strict liability; even if one sends an unsolicited advertisement by fax by accident, minimum liability of $500 per page attaches.