[RichardCA]

Back in the 70's there was a sex-ed book called "Show Me" which featured very frank photographs of both adults and children, completely naked.

It was subject to litigation at the time it was released and was upheld as not being obscene. But it continued to cause moral panics and was eventually taken out of print by the publisher.

But it was never banned and can still be found as a collector's item. And in the mid 70's it was completely normal to walk into a book store and see it on display.

<https://en.wikipedia.org/wiki/Show_Me!>