Yeah you're right. I'm fairly certain also that it's legal for private businesses / individuals to accept and sell other forms of money. Only when it comes to t

Yeah you're right. I'm fairly certain also that it's legal for private businesses / individuals to accept and sell other forms of money. Only when it comes to tax payment must you use the State issued currency or suffer repercussions. However we're reminded by Gresham's law that money overvalued by government will tend to drive out money that is not.