The spat between Apple Pay and a prototype rival system, CurrentC, is already relatively well documented. But according to a New York Times report, things go a little deeper: any merchant that’s signed up to use CurrentC is legally forbidden from accepting Apple Pay. The Times quotes numerous anonymous sources as saying that retailers who are part of the Merchant Customer Exchange, a group made up of merchants including the likes of Best Buy and Walmart, have exclusivity clauses in their contracts, meaning that accepting competing mobile payment options would result in steep fines.