The whistleblower said the two giant card companies knew their networks were being used to pay for illegal content on the porn-driven site.

The $35 billion takeover of Discover Financial Services (NYSE:DFS) by Capital One Financial Corp (NYSE:COF) creates the U.S.’ biggest credit card operator, and a major headache for rivals Visa ...

Visa and Mastercard operate on open networks, meaning they collaborate with various banks that issue cards under their brand. American Express and Discover, however, run closed networks ...