Reading through these discussions, this is the one question I haven't seen a good answer to. Would any of us be speaking out like we are right now if Apple had chosen to do server-side scanning instead of on-device scanning, just like every other company?
There are many options for personal server hosting where the hardware and software are open for reverse engineering and inspection, so you could, at least in theory, host a server you control without needing to use Apple's offering. On the other hand, smartphones are proliferated by a duopoly and there are no viable options for using one where both stacks are made completely open. No company has the capability to openly push a scanning feature like this into the Linux kernel in the same way that Apple can openly announce they're going to add their own version of such a feature to their own operating system, because the power dynamic is completely different.
It sounds like the magnitude of the backlash people are expressing can be partially explained by the fact that Apple has such a large foothold on the personal device market in a world where smartphones are increasingly becoming necessary to live one's life, and due to the inability to choose a privacy-respecting device that is also competent enough to satisfy society's new expectations for smartphone usage, there is no good place to hide.
