Scanning my photos for kiddie porn has no effect on my privacy, since I don’t have any kiddie porn.
Random warrantless searches of your property have no effect on you because you're not a criminal.
Warrantless surveilance of your entire digital life has no effect on you because you're not a criminal.
^ Those statements are contingent on what the powers that be define as "criminal." If the definition changes tomorrow then they'll have all the infrastructure and law in place to subjugate you as they please. At one point in time it was practically considered criminal to be Japanese in the USA, not that you would care because that has "no effect" on you if you weren't Japanese during that period of time.
If that were to happen I’d be here railing against it.
But as long as they’re just helping catch these sick freaks they have nothing but my support.
If they have all the infrastructure in place then there is no "railing against it" because by that time it's too late. There's no "railing against" nuclear weapons once we've all gone up in smoke. There's no "railing against" climate change once it's already too late and the planet is no longer viable for human life. The time to "rail against" technologies like this is not after they've been abused when it's too late, the time is NOW when the technology is capable of doing those things but hasn't yet gone that far.
Apple are implementing a system that is capable of scanning all the photos on your device against a database of images that can include images not related to child abuse, regardless of whether or not you have iCloud turned on. It doesn't matter that right now it disables itself when iCloud is off and it doesn't matter the database supposedly only includes child abuse images, it is CAPABLE of being an authoritarian tool at a moment's notice via minimal updates in the same way a nuclear bomb is capable of decimating a country with a few button presses even if the bomb is currently sitting in a silo.
You would say there's no issue with the patriot act because you're not a terrorist but it turns out the patriot act and its sister policies have been used to harass journalists and climate activists. It's not like there haven't been terror attacks on US soil since the patriot act was enacted. There were a 1000 other things the US government could have done to prevent more terrorist attacks globally but they chose the option of spying on every single citizen and violating people's constitutional rights instead. If you're actually interested in stopping "sickos" then support systems that actually combat the core issue rather than the "let's just police the entire public more" solution which won't actually stop "sickos" (terrorists use their own encrypted chat tools they make themselves according to various reports, so do child abusers most likely).
Nobody wants terrorists or child abusers in their community. Increasing the reach of warrantless, global spying programs is not the way to tackle the issue. Make no mistake, this system is capable of being a spying tool that bypasses end to end encryption regardless of how it's configured as of right now.
