At CNN, "U.S. offers download of new $50 bill"
One document obtained by the AP, a 1998 U.S. government business solicitation, mandated that "any color printer must include a tracing system that encodes system identification in any output. This will tie the output to the originating equipment so that forensic identification of the equipment is possible in the event of illegal printing of currency images due to failure or circumvention of the recognition system(s)...."