Crypto currencies are fundamentally in patible with the banking system. If you aren't a believer in crypto currency and want to buy something with bit coin or etherium, you have to convert real money to it before you transfer. And that's expensive because it's incompatible. The seller of the crypto currency do one of three things: They either have a pre established relationship with you, so they know you accept cash only, or be explicitly giving you credit. So if you don't follow those three rules, you end up like steve snia, who was out 70 thousand boxs because he sold some bit coin he got through pay pal, and it turned out it was a stolen credit