That's the view I would have thought most libertarians shared. On the other hand, how is possession/viewing of child porn more wrong than viewing pics/videos of murder? That also has a victim, but viewing the content doesn't cause the crime. The crime has already been committed. I can see the argument that within certain pedo communities, people are encouraged to produce CP, and that should be illegal in the same way that encouraging someone to commit violence or murder should be illegal. But what if you are merely a passive viewer of CP. How is that any more wrong than getting your jollies looking at murder videos?