Plantiffs also say the sheer size of the debit card market make their case big enough for the nation's highest court.
Last year's lawsuit against the Federal Reserve could be heard by the Supreme Court.
U.S. financial data is low-hanging fruit for thieves, experts say.
U.S. card data is low-hanging fruit for data thieves.
Kansas City economist says debit cap increases access to no-fee accounts, especially in competitive markets.
Merchant Payment Coalition says study claiming interchange impact did not include enough data.
Earlier this year, the Credit Union National Association tried to tout a survey of its members to support the claim that credit unions have been hurt by debit swipe fee reform.