He is a liar and fraud because he is claiming he is someone he is not to gain financially. . Yes, he has to prove he is Satoshi because that's not his real name. And he can't do it.
Am I allowed to go around claiming I am the real Santa Claus and then tell people I need money to pay my elves? Do I have to prove I am the real Santa? Or can I just get away with it?
How big is your belly? Do you have a beard?
No, but if I had a Big Belly and a beard, I could certainly fool a lot of people. LOL
