You would think libertarians would be unambiguously for freedom of speech. In Intellectual Property vs. Creative Freedom, Cathy Young discusses a literal book banning by a federal judge: he has temporarily enjoined "publication of a novel called 60 Years Later: Coming Through the Rye," based on copyright claims by "J. D. Salinger, author of the 1951 classic Catcher in the Rye." The judge is expected to decide soon whether to make the ban permanent. Yes, this is all because of copyright.
Copyright now lasts well over 100 years, due to continual copyright extension over the years--as Young notes, "When copyright legislation was first passed in the United States in 1790, the term of copyright lasted for 14 years, with the option of renewal for another 14."
Does Ms. Young want to abolish copyright, this obvious threat to freedom of press? Or at least return to the 14 + 14 year system? Why, no. She has figured out the optimal way to handle this: "Personally, I would support a term of 50 years, with a portion of revenues from any derivative work published thereafter going to the original author." Fifty years. Where she gets this number is anybody's guess.
This is libertarianism?