The proposed $30 billion antitrust settlement by Visa Inc. (NYSE:V) and Mastercard Inc. (NYSE:MA) is facing a potential setback as a New York judge has indicated that she may not approve the agreement. What Happened: U.S. District Judge Margo Brodie, during a hearing on Thursday, signaled that she is likely to reject the proposed settlement, Reuters reported. The settlement, announced on Mar. 26, aimed to resolve the majority of claims in a nationwide litigation that began in 2005. The settlement was designed to limit credit and debit card fees for merchants, with small businesses accounting f…