What if a noticeable amount of US dollars would be fake: could you make it public or would it hurt the economy too much ?

Exactly that might be the case...

https://imgur.com/gallery/nDPsFj6

Very impressive writeup. I can imagine this to be real but I havent done any fact checking.

If you commmit to practice fraud with this much effort, would it be possible to do the same with bitcoin?