I understand the intent, but feel that there are so many other loopholes that put much worse weapons on the street than a printer. Besides, my prints can barely sustain normal use, much less a bullet being fired from them. I would think that this is more of a risk to the person holding the gun than who it's pointing at.
Book piracy was huge I don't know what you're talking about. You could get professionally printed books or you could always just photocopy them.