bannedbook.org (禁闻网, pro-Falun Gong media)

The main Chinese name is 禁闻网 which stands for "banned news network", and is more accurate than the domain name "bannedbook" since the majority of material published appears to be recent banned articles.

Classifying this as Falun Gong media because most or possibly all of the sidebar recommended websites 推荐网站 are also Falun Gong media e.g. as of 2020-04: https://web.archive.org/web/20200427221744/https://www.bannedbook.org/ includes The Epoch Times (明慧网, Falun Gong media) and https://hongzhi.li/, so yeah, not much doubt.

From this we deduce that the "banned book" in the domain name originally likely referred more specifically to the banned Falun Gong sacred books: Canonical Falun Gong texts (法轮功的经典著作).

TODO who is behind this website? They store full text copies of banned articles, e.g. https://www.bannedbook.org/bnews/baitai/20190816/1175647.html is a full text copy of http://yashalong.blog.caixin.com/archives/188877 which is mentioned at: Comparisons between the CCP and Nazi Germany (纳粹德国和中共长得很想).