Say that you're an official with the Chinese Communist Party (CCP). You have huge stacks of brochures of anti-CCP materials. You've got them scanned and hashed. Next you call Apple and say, "Please alert us if similar imageries appears in your customers' devices. My assistants will send you weekly updates of the required hashes." Apple would say, "Sure, we're just following your law..."

Hence when a Chinese photographs such brochure "in the wild" using an iPhone, someone from "the government" will knock the next day and "strongly enquire" about yesterday's photo. Likewise when a Chinese minor receives an iMessage containing such brochure.

This is just _one_ example case of "extension" of the CSAM database as seen fit by some regulatory body.