WASHINGTON — A "dangerous cycle of debt" is trapping too many credit-card holders, making it increasingly difficult to protect their financial security, according to a report. About one-third of cardholders pay interest rates in excess of 20 percent, according to a report from New York-based think tank Demos. Also, borrowers with one slip-up can incur a "cascade" of penalties and end up in a "trap" of high-cost debt, the report said. "The excuse of risk-based pricing is used to justify everything. These prices go far beyond pricing for risk. Some of these interest rates and payment fees seem to not...