I have limited time so I'll get to my main point.
In chapter 16 of the Ethics of Liberty, Rothbard is using force to coerce Mr. Black into accepting the terms of a contract that he never agreed to. You can rationalize it any way you want but the fact remains you are using force to coerce someone into doing what you think is morally or philosophically correct without any agreement or contract with that party. That is authoritarian, not libertarian.
"To deny intellectual property is to deny self-ownership." I also disagree with this statement. Even if they made 1000 clones of me I still own myself. Whether or not YOU can tell the difference is irrelevant to my own self-determination.
NOTE: I am not advocating violence in any way. The content of the post is for intellectual, theoretical, and philosophical discussion. FEDS, please don't come to my house.