These premium cards have become a flashpoint in negotiations between the country's largest retailers and the Visa and Mastercard networks. Large merchants and Visa and Mastercard are still embroiled in negotiations over litigation that started in 2005, when retailers sued the networks, saying they violated antitrust laws by inflating swipe fees. While some merchants settled the case in a record settlement announced last year—Visa and Mastercard admitted no wrongdoing—a separate class of retailers are still fighting for changes to the networks' rules, including those that require stores to honor all of a brand's credit cards.