"Prohibits drawings, sculptures, and pictures of such drawings and sculptures depicting minors in actions or situations that meet the Miller test of being obscene, OR are engaged in sex acts that are deemed to meet the same obscene condition. The law does not explicitly state that images of fictional beings who appear to be under 18 engaged in sexual acts that are not deemed to be obscene are rendered illegal in and of their own condition (illustration of sex of fictional minors)."
1"* Whether the average person, applying contemporary community standards, would find that the work, taken as a whole, appeals to the prurient interest,
* Whether the work depicts/describes, in a patently offensive way, sexual conduct or excretory functions[2] specifically defined by applicable state law,
* Whether the work, taken as a whole, lacks serious literary, artistic, political or scientific value. (This is also known as the (S)LAPS test- [Serious] Literary, Artistic, Political, Scientific.)"
21 http://en.wikipedia.org/wiki/PROTECT_Act_of_20032 http://en.wikipedia.org/wiki/Miller_testFrom what I was just reading it seems legal. Even if the picture itself is kinda creepy.
And to your question of encourage or discourage by things, I find it's completely personality dependent. Because there most likely are pedophiles that suppress their urge through masturbation by looking at child porn. And there are others who makes the urge worse. You only hear about the latter because the former are able to keep it a secret.