If only it caught abusers, it would be great. Just think about what kids do while teenagers, throw in some poor judgement. Kids being kids. Is it a good thing that there should be a system in place to "catch" this? To involve strangers in their most intimate and vulnerable private communique?
That's just one argument on "even if everything works exactly as intended, it's still a terrible idea".
Then add malicious use of such a system once in place. We know such systems are misused ALL the time. So I would bet good money that someone, somewhere, will instead use it to neatly collect CSAM material.
Not to mention other malicious use of surveillance whereby you just add some hashes for files completely unrelated to CSAM. I'm not talking about the slippery-slope of "let's include some gay porn in the mix", but rather stuff related to political opponents, and what not.
It's a false dichotomy to suggest the trade-off is "catch some abusers" vs "catch no abusers". It's a "catch some abusers" vs "violate privacy of minors | remove e2e encrypted communication | etc"
These measures are only likely to lead to the arrest of a small portion of abusers, while opening a massive avenue for government overreach across the entire population.
I would assume that very few to none of us on here are pedophiles, and we're aware this is going on. It stands to reason that the pedophiles are also aware that this is going on, and the vast majority of them are going to adjust their behavior to avoid this scanning. Doubly so once a few arrests are made.
The balance of those issues is subjective, though.
Exactly. A handful of actual abusers will be caught and the rest will change their methods. The rest of us will have a system looking over our shoulder for the rest of our lives with an ever-expanding scope of uses. Not exactly a great trade-off.
Why isn't that better than catching none of the abusers?