In a bid to stop (or at least slow) people from purchasing and then unlocking and reselling iPhones, Apple announced this weekend it will limits sales of the phone to two per person. In addition, the company also said it would refuse to let people pay in cash for the phones, insisting on credit or debit card payments so sales can be tracked.

Last week, Apple Chief Operating Officer Tim Cook said a fifth or more of all iPhone users are buying these units with the intention of unlocking access to other carriers, totaling about 250,000. While Apple is reportedly making some healthy profits on each phone sold, some analysts believe it also receives a whopping $18 per month from AT&T for each iPhone customer, meaning unlocked iPhones are costing Apple millions of dollars.