While it seems that Karl-Erik understands copyright quite well, he offers no argument in favour of it, except the traditional commercial benefit to authors/publishers, albeit at the expense of public liberty (and persecution by corporations).
He does recognise the goodness of moral rights and the right to privacy, along with the inescapable logic that the fruits of one's intellect are one's intellectual property.
However, there still remains unexplained, the peculiar illogic that one should continue to own one's property even after one has sold it.
Justifying slavery by rote arguments of its commercial benefits to slave owners may well be unassailable on economic grounds (even if it turns out to be assailable upon hindsight). However, what we have today, to extend the allegory, is a situation where all slaves have become expert escape artists to rival Houdini. Whilst it's possible for a slave owner to visit the local towns to see if they can find any of their slaves still in the vicinity and obtain the services of the law to assist them reclaim their property, even the stubborn should soon see that despite the economic advantages previously enjoyed, the modern reality can no longer sustain them.
There have always been ethical arguments against copyright, but they have always been impotent against commercial priorities. What we have today is not so much a misunderstanding of copyright, but a misapplication. It could, perhaps a decade or so ago, be effectively applied to a thousand commercial publishers with real commercial benefits to the monopoly holders (notwithstanding the probably greater hidden costs), however it can no longer be effectively applied to a billion online publishers.
It doesn't matter how well you understand copyright, it is unethical, ineffective, uneconomic, irrelevant, and redundant.
What matters is how well you understand reality.
It is simply no longer practical to enforce, regardless of any theoretical or moral arguments about its moral or economic benefits or shortcomings.
The only way, in fact, that I can see any way to effectively enforce it now would be to mandate "trusted computing" with a central root authority. That way lies madness -- indeed, fascism. For it amounts to central control of the presses.
Presumably government control -- if it was not at first, that would quickly change as whoever controlled the certificate root authority would have the machinery to crown himself emperor of the planet and start issuing royal proclamations binding on everyone.
Just the ability to "unpublish" anything they didn't like would give them powers of censorship medieval kings could only aspire to. Nevermind the hostage-taking capability of shutting down the information age and all advanced machinery and tools in any given area, quite selectively. Push the button and that province with the troubling insurrectionist rabble-rousing not only is muzzled, but sent back to the Victorian Age technologically. No need to actually *bomb* them back there; just click the gold-plated Imperial Three-Button Mouse and turn off their lights and other high technology. Wait until they send postal letters begging for it to be turned back on if they promise to behave. Etc. Etc.
The scary thing is that there have already been a few attempts to legislate such capabilities for being centrally controlled be built into all electronics, supposedly for the benefit of the copyright industry. Even if there's no deeper conspiracy by those with much greater ambitions than perfect copyright enforcement, they'd be creating the mechanism by which freedom could be switched off as easily as turning off a light, and sooner or later someone would use this mechanism in just such a fashion. And the resulting dictatorship could be long-term stable. Guerrilla insurrection would be the only possible form of opposition given the powers of such an empire. Any attempt to establish a rival, free technological ecosystem would presumably be subjected to denial-of-service attacks, likely using EMP weapons. Only after the central authority was toppled would it be possible to set such a thing up -- and whoever got to the throne room and bumped off Emperor Bush III or whoever would be sorely tempted to just sit down in it himself and set himself up as Emperor Bin Laden I or whatever. :P
Basically, the central authority would be the "one ring to rule them all" as in a certain work of mythology. Tending to corrupt all comers, but really needing to be destroyed.
You own your mind and anything in it, your ideas and the products of your intellect.
You own your paper, your ink, and the ideas embodied in them.
Is there a moral or economic ground to try and disconnect these ideas from their tangibles and give them legal property status on their own?
Certainly you have the exclusive right to what is in your mind, but why should you have an exclusive right to what is in another's mind, or other property, even if it is indistinguishably similar to something in yours?