You're all assuming that predators who are already deliberating using apps which are encrypted to share CSAM won't just move to something else where there is encryption – which will always be possible unless the EU fines a way to ban maths or reverts back to the pre-digital age.
This might catch the odd moron sharing stuff on Facebook or on their phone, but I doubt it will stop the average offender was is already going out of their way to use encrypted apps/services.
But okay great, at least you catch the morons I guess, but at what cost? Here in the UK it's pretty common to be arrested for tweets at it is. There's no doubt in my mind this will be used to catch individuals committing speech crimes who are currently getting away with it because they share their opinions behind closed doors.
> but I doubt it will stop the average offender
I strongly believe it will catch the average offender. The average human doesn't have a clue about cryptography.
It won't catch all of them, of course. My point is that it is invalid to say that it won't catch anyone.
> but at what cost?
EXACTLY! The problem is that whoever controls the list of illegal material can abuse it. We fundamentally cannot audit the list because the material on this list is highly illegal. There is a risk of abuse.
"It won't catch all of them, of course. My point is that it is invalid to say that it won't catch anyone."
Sure, but wouldn't they quickly learn once people are getting caught?
No, they wouldn't. People were getting caught before encrypted apps. People are still getting caught on unencrypted apps today, even if it's easy to install an encrypted app.
And predators who get in contact with kids have to do it over social media that the kids use. Those ones would be affected by ChatControl.