Visa Countersues Wal-Mart In Debit Card Dispute

Visa Inc. filed a lawsuit against Wal-Mart Stores Inc. on Wednesday, claiming the retailer secretly began testing a protocol that eliminated the need for signature verifications for transactions paid for with a Visa debit card.

The lawsuit comes about a month after Wal-Mart had sued Visa, saying the payments network operator was resisting the use of personal identification numbers (PINs) by customers for purchases made on debit cards at Walmart stores.