The crimes related to having or distributing child porn exist to stop child abuse. Or at least they should. If no children are being harmed, there's no point in enforcing it just because it's creepy.
Actually I think making the content illegal is a stupid way to stop it, anyways. Once the information exists the crime has already happened. Distributing the information doesn't make the crime worse. Going after the consumer is an ineffective way to ban something. It doesn't even work for physical products like alcohol and drugs. Alcohol isn't creepy, I guess.
Well the idea is that you limit the creation of supply by punishing both that and the demand side. Yes, it clearly doesn't work for drugs, but there are different outside forces at work.
If I'm busted for pot possession, worst case scenario is jail time, but that's unlikely for a number of reasons. One thing is that number of people who smoke weed is huge, even though it's illegal, we would never have the money to aggressively target even any significant portion of pot users. At this point there's almost no social stigma, so it's even likely that a good number of police are sympathetic and think the laws are stupid.
With child pornography the social consequences to being caught can be basically the end of professional and social life. Police are far less likely to sympathize, you're targeting a much smaller group. The illegality of possessing child porn carries enough consequences that it unquestionably scares the crap out of at least some possible consumers rendering them inert.
If the ownership of child pornography were legal tomorrow, there would be an increased demand, and producers would rise to fill it, which by definition results in more abuse. So, yes I do think the prohibition on child porn is useful.
What the man in the article produced, however, was not child pornography.
