Whoa people. There are no coins in Bitcoin, just numbers. A "tainted" coin means one of the accounts in your transaction DAG was of questionable legality. Given time, every account will become "tainted". The only interesting question is: What happens if a court orders a "tainted" transaction rolled back?
What court do you think would have the authority to even speak about currency that doesn't belong to any country ? And even if it did, or try to do,
i hope you understand that noone can "order" rollback of transaction on a decentralized network.
One day, if nodes become heavily centralized, this could be possible i guess, altho i hope it won't happen.
Any court.
I understand. Judges, on the other hand, still seem to be living in the 20th century.