Lots of people sharing the fediverse csam studies, but I really want to draw attention to this comment from one of the people behind it:
"det@hachyderm.io - The Japanese server problem is often thought to mean "lolicon" or CG-CSAM, but it appears that servers that allow computer-generated imagery of kids also attracts users posting and trading "IRL" materials (their words, clear from post and match metadata), as well as grooming and swapping of CSAM chat group identifiers. This is not altogether surprising, but it is another knock against the excuses of lolicon apologists."
Professionals are trying to warn you about this stuff. Remember this when you consider this site twice tried to allow this kind of content. It makes your community dangerous. You can argue all day about whether lolicon or cub are true pedophilia but experts are trying to tell you that pedophiles come on the same train when you allow it. Don't let your guard down about these kinds of content policies.