Ars Technica’s piece details a nice reductio ad absurdam argument against selling downloads:
Consumers in some European countries have the right to return items with no questions asked for a specified time period after purchase. The Norwegian Consumer Ombudsman says that Apple violates the country’s Marketing Control Act by not offering a cooling-off period for music purchases, as Apple’s terms of service have no provision for refunds.
Obviously Apple and other sellers of downloads can’t abide a return policy, as people could buy, copy, and then “return” files at virtually no penalty in time or effort. (People can buy, rip, and return CDs and DVDs but it’s a bit of a hassle.) So they implement DRM schemes to restrict copying. Those schemes interfere with your right to use something you own.
If companies want to claim the benefits of commerce, they have to put up with its limits. Q.E.D.