The rights associated with patent, trademark, and copyright are valid legal rights (at least in the case of recent works), granted by Congress by its authority under Article I section 8 "To promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries".
But not all rights are property rights. If something is merely secured to you for a limited time, you don't own it. Lease, maybe. Own, no.
It follows that copyright infringement is not stealing.
Furthermore, under the Constitution, we do not balance the interests (let alone the supposed inherent rights) of the copyright holder against those of the public. The power Congress has is to promote progress, i.e. to serve the interest of the public. The interests to be balanced are the public's interest in copying freely and the public's interest in having more to read, see, hear, and copy. The latter is served, in a society where few have the leisure to pursue artistic activity full-time, by enabling people to make a living at artistic activity.
There's one other argument for copyright as property. It says that artists and thinkers inherently own any art or idea that they create, just because they created it, regardless of any government's pronouncements, and regardless of differences between ideas and tangible property.
But is creationism a good model for artistic activity? Is this how it really works: "In the beginning the world was without form and void, and darkness was on the face of the waters. Artist said, 'Let there be art.' And there was art."? Or is it more like an eternally-evolving noosphere in which timeless themes are repeated with each generation's particular variation?
Suppose there are two groups of people, and in each group a hundred people make up a hundred stories. In one group, each person is put in solitary confinement until they've written one story. The stories are sold to immortal corporations, and no story may be reproduced in whole or in part except for the financial benefit of the corporation that owns it, until seventy years after the death of the corporation (which never happens, of course). In the other group, people tell each other stories, then re-tell the stories, embellish them to be more pleasing, modify them to illustrate a point, simplify them to reveal their essence, extend them to develop a character, and so on. None of the people own any ideas: when one person has an idea, that enhances rather than restricts other people's ability to have related ideas. No one gets sued for plagiarizing themselves by telling a story too similar to one they told and sold, because ideas are not sold. In a hundred generations, which group will have better stories?
If the intellectual-property creationist view were correct, the first group would produce better stories. It just ain't so. The public domain is an artist's greatest resource. Allowing works to enter the public domain benefits not only the public as "consumers" of art, but artists as well.
Everyone has a natural right to sing, paint, write, think, etc. as they please, regardless of any similarity between their songs, words, thoughts, and so on and those that have gone before. Artistic activity is the opposite of alienated labor, not just one more kind of it. "Intellectual property" has it exactly backward.
This posting is hereby placed in the public domain. You may copy it freely.