[JURIST] Four merchant groups have filed an antitrust lawsuit against Visa [corporate website], Mastercard [corporate website], and dozens of major banks, over interchange fees, which retailers pay to issuing banks to receive payment for transactions involving the banks' cards. The fees, says Hank Armor of the National Association of Convenience Stores (NACS) [group website], serve "as a hidden tax, both on merchants and consumers, and raises costs of all products." The plaintiffs, NACS, the National Association of Chain Drug Stores [group website], the National Community Pharmacists Association [group website] and the National Cooperative Grocers Association [group website], represent the operators of over 138,000 convenience stores, 60,000 pharmacies and 120 cooperative groceries. The defendants include Bank of America, Citigroup and JPMorgan Chase, among the largest US credit card issuers. Representatives from Visa called the fees a "fair mechanism for fueling growth and sharing system costs," while Mastercard issued a statement chiding the plaintiffs' suit as "another example of merchants wanting the benefits of accepting payment cards without having to pay for the value of the services they receive." Reuters has more.