It doesn't matter what the purpose of this move is. It's not "catch-up" at all. The scanning will happen on the devices using the users' resources, before uploading. See also: https://news.ycombinator.com/item?id=28309202.
Itβs catch-up in that Apple submits less than a thousand CSAM reports to NCMEC annually:
> According to NCMEC, I submitted 608 reports to NCMEC in 2019, and 523 reports in 2020. In those same years, Apple submitted 205 and 265 reports (respectively). It isn't that Apple doesn't receive more picture than my service, or that they don't have more CP than I receive. Rather, it's that they don't seem to notice and therefore, don't report.
> In 2020, FotoForensics received 931,466 pictures and submitted 523 reports to NCMEC; that's 0.056%. During the same year, Facebook submitted 20,307,216 reports to NCMEC.
I understand people's objection with Apple's on-device implementation of this scanning, but that didn't seem to be parent's objection. I was just trying to clarify.
If I were a US citizen, and I accepted that scanning cloud-stored photos for CSAM was neccesary, I would greatly prefer Apple's approach because any such search coerced by Government are protected by the Fifth Amendment. Whereas if the search occurs in the cloud, Government can force Apple or Google to search for whatever they want, using whichever algorithm they want.
