One of the interesting divisions among libertarians is the split between IP communists, like Damon, and pro-IP rights people, like myself. Some IP commies claim that the point of property rights is to create a system of efficient allocation for things that can't be used by everyone at once. There's no point in having a car, say, if you don't have a right to exclude others from using it whenever they want, because if they're using it, you can't. And if you don't divide up common areas into parcels of property, everyone will race to plunder whatever they can from the limited stock of resources. However, the molecular structure of cipro (or the sequence of words in a novel, etc.) is costlessly replicable. Thus allowing everyone to use it doesn't keep the inventor from using it. Therefore, there's no point in attributing a right to use that structure of molecules (or sequence of words, etc).
My reply is that property rights aren't based solely on the necessity of assigning entitlements of use to things that everybody can't use at once. We need to distinguish the moral basis of rights from the reasons we have for respecting other's rights. The basis for my right in my car is that I bought it from someone who had a right in the car. Your reason for respecting my right to my car is that we're all better off in a system that efficiently allocates entitlements of use for rivalrous goods. With IP, the basis of my right to a certain molecule is that I discovered it. Now, here's where the IP commie comes in… “But do we really have a reason to respect that right? Wouldn't we all be better off if we didn't?”
This, I think, is the hard question. John Locke, the ur-rights theorist, argued that you have a right of original acquisition if you “mixed your labor” with the thing, and if you “leave enough and as good” for others. The tragedy of the commons problems that show that property rights are required for leaving enough and as good (required, because if no one has rights to the commons, it disappears due to abuse and plunder), apply equally to IP, but in a different way.
Think of the land of ideas as an abstract commons — everyone can wander in and explore. The problem here is that the commons is such a vast wasteland that it is incredibly difficult to find the oases of value in it. The tragedy of the intellectual commons isn't due to everyone racing to take what they can before others get to it, but due to no one bothering to go into it to discover its amazing treasures. If there are no IP rights, some people will go into the commons for fun (open source-like folks), and will be happy to share what they find. However, most people will be discouraged if they know that they won't have rights over what they find there. And so many amazing, life-enhancing things will be left unfound.
The question is: Under IP communism, will the value that comes from the public diffusion of the things that are found make up for the value that is lost from the things that are not found, due to disincentive? And would this be a good enough reason to override the basic moral rights of discoverers and creators? Not easy questions.
The IP commie argument that in an open source world people will simply respond to different incentives, and therefore gladly contribute their intellectual effort for the commonweal, smacks too much of the regular commie argument that the abolition of property altogether will only bring out the best in all of us, which will bring forth utopia. We all know how that worked out.