That's still not an especially resounding success, or an especially relevant metric for us to understand the efficacy of FB's detection systems, and doesn't help us understand whether encryption of content is going to hurt hunting CEP.

For example, they might be spotting a large fraction via network analysis, or other metadata approaches. Alternatively, they might just hash every image sent over messenger and match those to known CEP. Encryption screws up one avenue, but not the other.

All it says is that the cops are terrible at finding this kind of content on FB, which is to be expected since they have only a very limited view into the platform. The only stuff the cops are catching that FB isn't is when they knock down someone's door and grab their FB password to look for stuff the filters missed.

> encryption of content is going to hurt hunting CEP.

Aren't we putting the cart before the horse? The problem is the exploitation of children, the secondary problem is that this exploitation is sometimes photographed and shared.

I don't believe that a strong solution the latter problem will have any impact on the former.