I've never seen anyone go to prison in the US for just reading child erotica. There have been people arrested for it sure, but they always get let off on first amendment grounds. I have seen a few arrested for distributing across state lines with payment. Guilty of capitalism I guess. That's why all the child erotica websites I've seen are hosted in the open in the US, but none charge for it.

It's most of the rest of the world where it's illegal. Where I've seen people going to prison for many years in multiple different European countries. Canada might be the worst. Saw someone go to prison for 10 years for reading child erotica hosted in the US. They read the legal statement saying it was legal in the US. And just assumed that Canada would be legal too.

Either way there are a lot of people around the world who would go to jail for reading such sites and that includes many non western countries as well. Most people don't have the first amendment protecting them. So that's why the sites are not allowed to be posted.