In the late 1990s, North Korean diplomats were caught passing supernotes. In August 2005, Chinese organized crime gangs were caught smuggling bills into New Jersey and Los Angeles.
As banks continue seizing the supernotes, about $50 million worth of counterfeit money has been found so far.
The ‘supernote’ appears to be made from the same cotton and linen mix that distinguishes U.S. currency from other currency with watermarks visible from the other side of the bill; colored microfibers woven into the substrate of the banknote; and an embedded strip, barely visible, that reads “USA 100” and glows red in ultraviolet light.
The supernotes could be made by someone who has access to government printing equipment, while security experts point to suspected criminal sources in North Korea, Iran, China and Russia.