Apple has announced that it will not accept cash or Apple gift cards as payment for an iPhone. If you, like me, have questioned the legality of Apple stores banning cash for iPhone purchases then this posting is for you. The reason Apple has given for the non-cash and gift card policy is that it wants to discourage unauthorized resellers from modifying the devices so they work on networks other than the intended carrier, AT&T.
As you can see in the below video from station KMBC in Kansas, the reporter talked with employees at an Apple store at where one worker admitted that "it's crazy" not to accept an Apple gift card.
Apparently, the pertinent portion of law that addresses this issue is the Coinage Act of 1965, specifically Section 31 U.S.C. 5103, entitled "Legal tender." This happens to be the section many are citing as proof that Apple's no-cash policy is illegal. It reads, "United States coins and currency (including Federal reserve notes and circulating notes of Federal reserve banks and national banks), are legal tender for all debts, public charges, taxes, and dues."
What that means, however, is that all U.S. money (be it bank notes or coins), "are a valid and legal offer of payment for debts when tendered to a creditor." In fact, there is no federal law that prohibits a private business, a person or an organization from dictating what currency or coins they do accept for payment for goods and/or services. Indeed, businesses like Apple are free to develop whatever nutty cash policies it likes unless there is a state law which says otherwise.
You can see the posting from the U.S. Department of Treasury here.