I've just read this in "Against intellectual monopoly" page 296 ( <a href="http://levine.sscnet.ucla.edu/general/intellectual/againstfinal.htm" rel="nofollow">http://levine.sscnet.ucla.edu/general/intellectual/againstfi...</a> ) :<p><i>Social norms are not a topic in which we are especially
expert. Still, it is a relevant topic: property rights are never
enforced only by the law-and-order system, or even by costly
private monitoring of other people's behavior. Broadly accepted
and well functioning property rights systems rest also, one is
tempted to write "primarily," on a commonly shared sense of
morality.</i><p>Then it quotes another economist, Eric Rasmusen :<p><i>Video rental stores and libraries, of course, reduce
originator profits and hurt innovation, but that is a
utilitarian concern. What is of more ethical concern is that
whenever, for example, someone borrows a book from the
public library instead of buying a book, he has deprived the
author of the fruits of his labor and participated in
reducing the author's power to control his self- expression.
Thus, if it is immoral to violate a book's copyright, so too it
would seem to be immoral to use public libraries. Libraries
are not illegal, but the law's injustice would be no reason
for a moral person to do unjust things. The existence of
children's sections would be particularly heinous, as
encouraging children to steal.</i><p><i>To entirely deter copying would require a norm inflicting a
considerable amount of guilt on copiers, since legal
enforcement of copying by individuals is so difficult. To
partially deter it would be undesirable for two reasons.
First, it would generate a large amount of disutility while
failing to deter the target misbehavior. Second, it would
reduce the effectiveness of guilt in other situations, by
pushing so many people over the threshold of being moral
reprobates. At the same time, the benefit from deterring
copying by individuals, the increased incentive for creation
of new products, is relatively small. I thus conclude that
people</i> _should_not_feel_guilty_about_copying_.