This is the part that's really infuriating to me that I've seen in several comments - this implication that the onus is on programmers or people who work in technology to somehow figure out a way to do this impossible thing, as if nobody has tried. And then they have the gall to say something like "I want both privacy and for us not to tolerate CSAM." without proposing any kind of theoretical solution.

If you can't even propose a hypothetical science fiction-esque way of achieving this, much less one that might actually be implementable now or in the near future (like, 5-10 years), you shouldn't get to have that opinion.

Come on, now. People are entitled to have any opinion at all. Even exceptionally ridiculous ones.