I hope that there will be a transparency report for how many reports happened and how many were found to be false positives.
Regarding China, the answer is probably “nothing”, but the system as it exists is not amenable to what I imagine their goals would be: only monitors the photo library (not messages) and requires a certain threshold of matches. The question is, I think, what today prevents China from requiring devices to attempt to match a database of pictures with a mandated match algorithm and a mandated reporting server. I believe (admittedly without any knowledge of the matter) that the same standard would apply to both.
Regarding China, the answer is probably “nothing”, but the system as it exists is not amenable to what I imagine their goals would be: only monitors the photo library (not messages) and requires a certain threshold of matches. The question is, I think, what today prevents China from requiring devices to attempt to match a database of pictures with a mandated match algorithm and a mandated reporting server. I believe (admittedly without any knowledge of the matter) that the same standard would apply to both.