She just advocated for the banning of a book.
"These documents are not, in my view, protected by the First Amendment and should be removed from the Internet."
She's making a pretty serious threat of violence here, isn't she? She isn't asking for people to voluntarily turn in their copies of the book or delete the copies from their computer or server. "Should be removed" is a clear threat.
Is she making an idle threat? Sure, she would never get away with it. That doesn't mean that threats against fundamental rights shouldn't be taken seriously and opposed. She made herself clear. If she thought she could get away with it she would indeed try to take this book away from people by force.
There are mountains of historical precedent for the banning of books, in the US (by localities) and around the world. It isn't "fantasy".