> Should we extend cp to make it refuse to copy such files? I hope you would say "no." So there's a line to be drawn somewhere. How do we decide where that line is?
But that's not a direct analogy: No one's restricting you from viewing that pdf or distributing it. BTW password-protected pdfs encourage such 'for-your-eyes-only' behaviour. That should be cause for more concern as far as free speech is concerned.