Кстати, за underage sex можно и на фанфикшен нете жаловаться

https://www.fanfiction.net/topic/9522/178725268/Reporting-someone

а вот на АОЗ можно

Sexually explicit photographs, videos, and other photorealistic images of children (also known as Child Sexual Abuse Material, or CSAM) are prohibited in the United States and on AO3. Users who embed, link to, solicit, distribute, or otherwise provide access to such material will be banned and reported to the appropriate authorities.

Stories and non-photorealistic artwork (such as drawings or cartoons) that depict sexual activity involving characters under the age of eighteen are allowed, provided that the works are properly rated and carry the appropriate Archive Warning. However, photographic or photorealistic images of humans may not be used to illustrate works featuring underage sexual content. This includes (but is not limited to) photographs of children, porn gifs, photo manipulations, computer-generated or "AI" images, or other linked or embedded images that could potentially be mistaken for photographs of real humans.

We understand that not all photorealistic images of humans are actually documenting the real-life abuse of a child or derived from illegal material, but we decided to use a guideline that can be uniformly applied without relying on subjective judgment. If the work appears to feature underage sexual content (as indicated by the "Underage Sex" Archive Warning or other contextual markers present in the work's tags, notes, or text), then the Policy & Abuse committee may require all photographic or photorealistic images of humans, regardless of age, to be removed from the work.

Does AO3 screen for quality?

No. We welcome creators and fanworks of all skill levels, and we will never remove a work on account of its quality, grammar, spelling, or punctuation.