Why can’t Apple (AAPL) keep enough iPhones in stock in its U.S. stores? One theory: Because so many are being bought to be “unlocked” and resold overseas.

We’ve seen plenty of anecdotal reports of tourists leaving the U.S. full of iPhones (or trying to). What happens after that? In some cases, apparently, they hit Craigslist, or their international equivalents. What we do know: If you’re willing to pay a premium, you can buy an iPhone anywhere in the world.

read it here alleyinsider.com