This is originally a post created by Roderick T. Long that I really enjoy. I am anti-copyright and I agree with a lot of the arguments made by him. I am posting it here simply for easy access and I take no credit for the original work.
Suppose I compose a poem and recite it to you. As a result, you learn the poem by heart. In effect, there is now a copy of the poem stored in your brain.
Who owns that copy?
The only answer must be: you do. You own yourself; you own your brain and the contents of your brain. If I owned the copy in your brain, then I would be a part owner of your brain, which would make you a partial slave – which is morally untenable.
Now in addition to owning your brain and the poem stored within, you also own, let's suppose, a pen and some paper. You use your pen to transcribe onto the paper the poem that's stored in your head. Now there are two copies of my poem in your possession: one in your brain and one on the paper. Who owns the second copy?
Once again, you do. You produced that second copy using nothing but factors that you owned: your paper, your pen, and your brain (with your neuron-encoded first copy of my poem). That second copy is yours – to keep, to burn, or to transfer.
Yes, to transfer. If you give or sell your copy to someone else, or if you use your copy to make a new copy to give or sell to someone else, or if you allow others to use your copy to make new copies, you are making a peaceful use of your own property. You are violating no rights.
"But," I protest, "that's my poem you're selling!"
No, it isn't. You're not selling any concrete copies of the poem that are in my possession – I still own those and can control access to them as I please. Nor are you selling the abstract object of which all these copies are instances. You can't sell an abstract object. Abstract objects can't be transferred. They are not scarce resources; one person does not lose access to the abstract object just because someone else has gained access. All you're selling is your copies of the poem. Which is your perfect right. They're yours to do with as you please.
"But," I protest once more, "I created that abstract object. That makes it my property!"
Well, what does it mean to own an abstract object? One thing it might mean is that I own all the instances of that abstract object. In which case I'm engaged in fraud if I claim to be selling copies of my work; if I still claim copyright in them, then I'm claiming to own the copies and so I've never really sold them.
But if owning an abstract object means owning all the instances, then it means my owning the copy of my poem in your brain. In that case, intellectual property is a form of slavery. If slavery is illegitimate, then so is intellectual property.
On the other hand, if owning an abstract object doesn't mean owning its instances, then what does it mean? In selling your concrete copies of my poem, you don't interfere in any way with my access to the abstract object. So what "ownership" of mine are you infringing?
Either intellectual property means slavery, or it means nothing at all.