You see? The online purchases are not as unregulated as they may seem. There are laws about them, and the online companies do follow those laws.
Trying to sell banned service to US customer is not much easier than trying to sell banned food. One may try but the interested troll only need to send a cease-and-desist to yet another payment processor one uses to sell to US, and the service is on square one, again.
Let's assume that's happened before anyway..
What if you use a foreign domain name?
What are the non-US based methods of receiving payment online?
Are there any viable foreign servers that are fast enough to service the US but whose country does not have patent agreements with the US?
He's just joking, right? Surely he has neither tools nor intentions to put someone out of business?