Funny, wonder why when I just searched Yahoo for "Libertarian property rights" this was the second thing that came up, from libertariannation.org?
There are millions of websites out there that purport to be things that they clearly are not. The site you found, is among them.
Interesting, but his arguments are mainly addressed by how copyright and patent law in this country were designed to operate, with a wide leeway for Fair Use and a quick expiration to the Public Domain. The arguments make sense only in our current warped system, with fair use dying due to fear of being sued into oblivion, copyright terms being effectively infinite, and patents being awarded for pretty much anything.