Shaun - thanks for posting. Interesting read and I too would not have seen it behind the pay wall.
I've prosecuted and defended many child pornography cases over the years. I can firmly say that trying to understand the people involved is a pointless endeavor. I've seen all types of people involved, some of which you would never expect, even a West Point grad. The one certainty is that these folks are typically very tech savvy and the landscape of the length they go to hide and exchange their materials is everchanging. (think putting external storage devices in the attic, or Limewire back in the day) This article is evidence of just how ever evolving these types of cases are.
The National Center for Missing and Exploited Children, located in Alexandria VA, does great work in this area. Link to their website below:
https://www.missingkids.org/HOME
This work is not for the faint of heart and one has to have or develop a very thick skin and be able to compartmentalize your work from your private life.
One time when I was prosecuting a case, the defense attorney came to me to discuss a deal. He was really lowballing me for the length of confinement we would accept. I asked him if he had looked at the evidence because the case was really worth more jail time than he knew. He says no, that he was a father and wasn't about to look at it. Totally forgetting the duty he had to his client. Idiot. Time for him to find another job.