Apple has instituted a policy in its stores to only sell two iPhones per customer, and they’ll now only accept credit cards according to Cnet, which posits that the credit card requirement is to create a paper trail. This started from Thursday—before that people could get up to five phones and pay cash. Associated Press has a quote from Apple: “Customer response to the iPhone has been off the charts, and limiting iPhone sales to two per customer helps us ensure that there are enough iPhones for people who are shopping for themselves or buying a gift,” spokeswoman Natalie Kerris said. “We’re requiring a credit or debit card for payment to discourage unauthorized resellers.” This move could be to stop the iPhones being shipped overseas, where the devices are being sold for a higher price. Apple reports it has sold 1.4 million iPhones to date, and estimates that 250,000 of those were sold to people intending to unlock them.