After reading that Apple now requires one to use a credit or debit card to buy an iPhone (to limit unlockers), Slashdot reminds us that Apple is not obligated to accept your hard earned cash, contrary to what you (and myself!) might think.
According to the U.S. Treasury FAQ:
There is, however, no Federal statute mandating that a private business, a person or an organization must accept currency or coins as for payment for goods and/or services. Private businesses are free to develop their own policies on whether or not to accept cash unless there is a State law which says otherwise.
Dang! That surprises me. Think you're getting back at a business by paying a bill with all pennies? They don't have to accept it!
Link. Via Slashdot.