Notice that again the conservative voice on slashdot is screaming about how FedEx doesn't want to transport certain goods. If the product was a pamphlet for a local union hall, the conservatives would say that FedEx was exercising their rights to free speech and freedom of association. But since the product is something that conservatives believe all Americans have god-granted rights to, FedEx's refusal to transport it is clearly a constitutional crisis.
In other words, FedEx is free to transport whatever goods they want, unless refusing them angers the conservatives. Then, FedEx must transport them in spite of their objections.