I have a right to free speech under the first amendment. That does not mean I have "Free Speech Property". Rights are not property. You can have rights over property, but the rights themselves are not property.
Claiming that copyright is property is not intellectually honest. As a creator of a copyrighted work, you can claim ownership of the original work and you have property rights to the original work. However, copyright extends only to the ability to copy that work. That ability to copy is not property. It is a right. Rights can only be infringed not stolen.