Today, U.S. District Judge Richard Leon ruled that the Federal Reserve did not appropriately fulfill Congress’s intent of the Durbin Amendment, a provision of the Dodd-Frank legislation.

In effect since October 2011, the existing Durbin interchange rules, i.e. 21-cent cap, will remain in place pending revised regulations.

“The Board has clearly disregarded Congress’s statutory intent by inappropriately inflating all debit card transaction fees by billions of dollars and failing to provide merchants with multiple unaffiliated networks for each debit card transaction,” Leon said in his ruling.

More news and implications to follow.