Your ideas, by the way, could equally well be applied - and are, by some fanatics - to violent video games, and yet I bet you oppose efforts to even curtail their availability, let alone imprison their fans.
I would really like to emphasise that I think that someone who's interested in collecting 10G of pictures of kids being raped is obviously pretty sick. If I found that someone I knew had such an interest, I'd probably never speak to them again. If I had kids, I'd keep them the hell away from such a pervert. But illegal? For having copied some files, but having had nothing to do with the crime involved in their original creation? Those pictures are depictions and records of a crime, but they do not embody it.
The whole concept is ludicrous and I can't believe I am so alone in pointing that out. If you have a picture of a murder, and I copy it, we haven't somehow created another murder out of the ether. If I possess a picture of someone doing illegal drugs, I don't magically become partially responsible for the drug use. I think a reasonable person would agree up to here with everything I said. So why does all rationality fly straight out the window when it comes to a crime that happens to involve a child? The arguments weren't valid before, but change the subject to an emotionally charged topic and suddenly they make perfect sense?
I just don't buy it. You can't cut and paste pictures of crime, and in doing so create more crime. You can't create more crime by viewing a recording of crime. I am utterly baffled why anyone would argue otherwise.