Shortly after Valeria Carranza moved into her Takoma Park apartment, she got her first electric bill from Pepco. In addition to billing Carranza for the power she used, Pepco added a $390 charge it called a “balance forward.” When Carranza called, the utility told her she had to pay the deposit to “establish credit with Pepco.”

What that meant was that rather than run a credit check to determine if Carranza was a risk, Pepco was charging her up front just in case she might miss any future payments. When Carranza refused to pay, Pepco threatened to shut off her electricity.