The lending of money, especially at exorbitant interest rates. Many states have usury laws that cap interest rates, but a 1978 Supreme Court rulings allowed credit cards or other lenders to ignore those laws if the lender is headquartered in a state that does not have them. Most major card issuers have located their headquarters in states with no usury laws. That effectively negated state usury laws, and hence there is no cap on most credit cards’ interest rates. They can charge usurious rates, legally.