Someone in the comments linked this article about the history of child porn swapping on the deep web, and I'm reading through it because it's pretty interesting (but nauseating and heartbreaking as well), but one thing has me stopped in my tracks.

Child porn has only been illegal nationwide since 1978?!?! I can't even begin to wrap my brain around that! I never EVER would have guessed that it was so recent! And before that, you could buy glossy magazines of underage porn off magazine racks, right next to the adult porn magazines?

How did people justify this? How did it take so long to be banned? Did the police never stop to think about how the children in those magazines were being abused? Can anyone who knows more about this, or who was alive in 1978, make this make sense to me?