If your going to do business in a country you must adhere to the laws of that country
I don’t disagree with that sentiment Ax but the question still very much remains … exactly where does the transaction take place?
It is absolutely NOT illegal for that person in .. Maine .. (cause I can’t spell your example state 
) to go to Amsterdamn and buy pot.
To my knowledge it still has not been determined where transactions between two countries actually takes place in respect to the net.