I can't believe it's not a greenback

Counterfeit $100 bills are circling the globe, and their story is intriguing. These bills are so well done that that it's next to impossible to tell that they're fakes. They've been dubbed "supernotes" because of their precision.

Experts say these are the most sophisticated examples of counterfeit U.S. currency ever seen. They are made of the exact same cotton and linen mix from which legitimate U.S. currency is made. They even have the proper-colored microfibers and an embedded strip that glows under ultraviolet light... both key pieces of currency that are supposed to be difficult to counterfeit. The fake bills also have the proper microprint and optically variable ink (OVI) that distinguishes authentic U.S currency.

Authorities say the bills haven't been printed in large quantities. Only $50 million of supernotes have been found since 1989, which is estimated to be too little to even cover the cost of the sophisticated printing process required.