The U.S. Department of Justice has launched an antitrust lawsuit against Visa, accusing the payments giant of exploiting its dominance in the debit card market to stifle competition and impose exorbitant fees on consumers and businesses. The suit, filed in the U.S. District Court for the Southern District of New York, claims that Visa uses its market power to pressure merchants, banks, and financial institutions into using its proprietary payment processing network, resulting in billions of dollars in fees that are ultimately passed on to consumers.