"Money is created through forms of credit and debt, i.e., when banks make loans and debtors accept them, the money instantly exists. Only a fiat system can allow this form of money creation."
http://www.theoildrum.com/node/4611
EDIT
I reverse my position. Sure, banks have the prerogative create money, but their ability to do so is based on people using the banks. Once banks no longer provide value for people, they lose their money creation ability. So, even banks are limited in their printing of money.