Isn't the best to ask a lawyer from current country.
Each state in the US have different law's you can say they are 90% similar with few differences, other country's have different law's as well and each treat copyright different(In Russia and China there are no copyright Law's you can simply take a game and make an exact clone of it and no one will bother you, if you want to sue someone he will be under the Law's of the current country he's In)i can't give any advice else than go ask a lawyer.