Comment by aspenmayer

Yes, this is a thing. Supposedly such a thing was used in a recent attack. 3D printers are not able to determine intended operation of their printed output from their print job inputs, whereas counterfeit money has no legitimate purpose, so anything that looks “close enough” for an automated system to detect is probably close enough to fool a human if passed to them as if it were the real thing. I think preventing counterfeit money is a broad enough social good/benefit that a broad cross section of industry, government, and private individuals and groups have decided to work together to make it harder to produce. I don’t see who is harmed by this, besides people trying to print their own currencies for their own purposes, some of whom aren’t trying to make counterfeit copies of actually-existing currencies, but I think they are already going to have to worry about the counterfeit problems themselves if their currency is used outside of controlled conditions by trusted parties.