To say that copyright does not protect any natural right is not to say that it lacks any moral justification. We naturally frown on unauthorized and misattributed copying. A singer who claims authorship of a song written by another commits a sort of fraud on his listeners. Most of the time, that sort of fraud does not rise to the level of materiality, and thus does not justify litigation. We typically do not rely to any substantial detriment on the accuracy of an expressive work's description, after all. If we like a work, we like it, regardless of its source. Misdescriptions of authorship can trick us into buying the wrong expressions, however. You might, for instance, buy tickets to a Djelimady Tounkara concert only to find another, lesser guitarist on stage. That would naturally rouse your indignation.
We don't need copyrights to vindicate that sort of wrong, however; common law and various state and federal statutes already afford many remedies for it. Consumers of misleadingly labeled goods or services can plead fraud under tort law and breach or promissory estoppel under contract law. The licensee of a materially misdescribed work would enjoy a strong contract law defense, one voiding any agreement alleged by the licensor publisher. An author who sees her work sold under another's name would, as a wronged competitor, have standing to sue for unfair competition under state or federal law. The publisher of such an author might likewise enjoy legal and equitable remedies for passing off. The Federal Trade Commission and its many state counterparts can protect consumers and competitors of falsely labeled expressive works, while various federal and state executive officers can fight such wrongs with the criminal sanctions levied against the many guises of fraud.
Those legal tools give us ample ways to discourage materially harmful misdescriptions of expressive works. We don't need copyright to satisfy our moral intuitions on that front, and most people's condemnations against unauthorized copying don't go much beyond harmful lying. If you make an unauthorized copy of a CD and give it as a gift to your friend, for instance, do you feel guilty of committing a moral wrong? Probably not—even though you would probably thereby have committed copyright infringement. You can admit to breaking the law in such a case without admitting to violating a natural right. Thus does a good driver on an empty road speed with a clear conscience. We recognize copying limits, like speed limits, as legislation designed to maximize social utility, created by statute for presumptively good reasons and thus, unless manifestly inefficient or inequitable, enjoying some claim to our obedience. We follow such laws out of habit, conformism, or fear—not because they protect natural rights.
So go the moral intuitions of most folks. Authors, admittedly, sometimes express profound outrage that unauthorized copying, even when it gives credit where due, equates to theft. Their understandable pique does not, however, establish a natural copyright right. The non-rivalrousness of expressive works means that copying does not hinder the use or enjoyment of anyone's copy. A painter fully owns his canvas even if another photographs it without his permission, for instance. What authors care about in such instances is not the use and enjoyment of their works, but rather their lost copyright revenues.
Copyright can provide authors with revenue, a benefit that infringement threatens to reduce. Authors thus naturally feel disappointment and anger when their works suffer unauthorized use. But that hardly shows that copyright infringement violates a natural right. It only shows that authors, like almost everyone else, prefer more money to less. There can be no copyright infringement absent copyright protection. Only by circular reasoning, then, can the complaint that infringement reduces authors' revenues justify copyright.
[NB: The above text comes from chapter 1.5, § C.3 of my draft book, Intellectual Privilege: Copyright, Common Law, and the Common Good. Please note that I will soon renumber it "Chapter 2," and adjust all subsequent chapters accordingly. You can find a PDF of the entire chapter, including footnotes, here. As always, I welcome your comments.]
[Crossposted to Intellectual Privilege and The Technology Liberation Front.]