Give this a read: http://www.washingtonpost.com/news/morning-mix/wp/2014/10/16/john-grisham-says-sentencing-for-child-porn-offenders-is-too-harsh-they-arent-real-pedophiles/
Incidentally, I'm something of a connoisseur of the more unpleasant side of the Internet; the nastier side of human nature is something that fascinates me a wee bit. However, in almost two decades online, I've never seen, nor found myself presented with the opportunity to see, child pornography. The excuse that this is something you can accidentally stumble upon is pathetic. Either you've looked for it, or someone's sent it to you.