is the onus on an artist or on an "auction house" to vet buyers. If post sale it turns out the money was fraudulent, does the artist need to pay it back?
In crypto terms. You the artist simply put a NFT up for auction at OpenSea. You the scammer happened to purchase the artwork on OpenSea. However KYC is not well enforced, enabling for money laundering between the two wallets.
Auction houses are known to be on the trick -- that is passively mainly/ they don't care and work to "pump" the prices of artwork. But of course law enforcement agencies know about it too.
It shouldn't be illegal: people should be free to buy what they want. But let's not hide behind our noses.
Maybe? IIRC, if you unknowingly buy stolen property, and they trace it to you, I think you have to surrender it to its rightful owner (without compensation from the police).
https://www.wilsonelser.com/files/repository/PHLY_Article_Cl...
Doing business with criminals can bite you, even if you were not participating in a criminal enterprise.
No. Normally you have to return items that were stolen from someone even if you purchased them without knowing they were stolen. But money is an exception. See:
https://en.wikipedia.org/wiki/Nemo_dat_quod_non_habet
(I don’t know whether Bitcoin would be treated as money for these purposes…)
Law on receiving stolen goods is vague, complex, and jurisdiction-dependent. But in some cases, if the money you get paid is "the same" money that was stolen (something that's actually much easier to show with Bitcoin, where every input to every transaction is another transaction's output), and you know about the crime, yes. See People ex Rel. Briggs v. Hanley.
https://www.reddit.com/r/CryptoCurrency/comments/sohojt/mela...
You can walk in the river instead of trying to cover your tracks.