Brown has copyrighted his book, On X. Green, in buying, signs an agreement not to copy it. So far so good. Then Black reads Green’s copy of On X book which he left lying on the table.

Rothbard’s position on Black’s rights is as follows.

For suppose that Brown builds a better mousetrap and sells it widely, but stamps each mousetrap “copyright Mr. Brown.” What he is then doing is sellingnot the entire property right in each mousetrap, but, the right to do anything with the mousetrap except to sell it or an identical copy to someone else. The right to sell the Brown mousetrap is retained in perpetuity by Brown. …

A common objection runs as follows: all right, it would be criminal for Green to produce and sell the Brown mousetrap; but suppose that someone else, Black, who had not made a contract with Brown, happens to see Green’s mousetrap and then goes ahead and produces and sells the replica? Why should he be prosecuted?

The answer is that, as in the case of our critique of negotiable instruments, no one can acquire a greater property title in something than has already been given away or sold.

Green did not own the total property right in his mousetrap, in accordance with his contract with Brown — but only all rights except to sell it or a replica. But, therefore Black’s title in the mousetrap, the ownership of the ideas in Black’s head, can be no greater than Green’s, and therefore he too would be a violator of Brown’s property even though he himself had not made the actual contract. (The Ethics of Liberty, 123)

First of all, this particular example sounds more like a patent to me rather than a copyright.

But anyway, let’s replace the mousetrap with a book. Brown writes a book and sells it to Green who signs a “will not copy” or non-copying agreement (NCA).

Black then casually picks up Green’s book, while both of them are talking in a coffee shop, and Green has gotten up to get his order, and leafs through it.

Why have copyright in the first place? Not to impose an arbitrary restriction but to ensure that anyone who reads a book pays for this privilege. Clearly, copyright has failed to make Black pay. If we want to be true to the spirit of copyright, then we must either prosecute Black for reading without paying or prosecute Green for allowing Black to do just that.

The NCA is a weak protection indeed. The spirit of copyright insists that Green be made into a “guardian” of Brown’s ideas, along with Brown himself. He is bound as if by an oath to not even talk about Brown’s book, because that might inform other people of its content in such a way as to reduce Brown’s rightful income. He must actively seek to prevent others from learning from On X or be in violation of a contract. Green is recruited into this sort of servitude to Brown simply by virtue of buying Brown’s book.

And that just seems absurd.

Not consider the implications. If Black’s idea — though he wickedly got for free as a result of Green’s lamentable lack of vigilance — is his rightfully, and he is not duty-bound to forget at ASAP, and if the paper on which prints this idea is also his (nothing unusual here), then why can’t he “copy” this combination of form and matter to his heart’s content?

The only reason is utilitarian: society might be better off when Black’s rights are crudely restricted by our inconsistent notion of copyright than otherwise, etc. But no libertarian principle or natural rights seem to be involved.

Odd, isn’t it?