Are the iPhones at US airport duty free shops unlocked?

Be very careful, any iphone purchased from a non-official source & advertised as unlocked most likely was hacked to unlock it and will cause nothing but problems in the future. Since the iphone warranty & support is country specific(only valid in the country of original purchase), determining the original source of these phones is problematic. We get posts all the time from people who purchase these phones & unfortunately, there is not much that can be done to help them.