Actually, it is not illegal for a private corporation, entity, or person to print their own unique form of money. Local banks do it for 'community dollars' to keep money in small towns for example. As for dictating the value of the US Dollar, nobody specifies the exact value. It is a fiat type of currency. So the collective dictates the value based upon what two parties (buyers and sellers of good/services) are willing to exchange for it. This is the basis for Bitcoin for example, and almost all other currencies on the planet.