alt Hacker NewsSurveillance which violates the privacy or other rights of lawful citizens is worse than crime, I argue. The criminal fears the police, but the government obeys nobody.
Security cameras in public areas, I don't have a problem. Government mandated scanning software running on my PC, yeah, I have a problem. It amounts to a warrantless search.
It's no more "warrantless search" than object recognition in your photo app. Signal deliberately misrepresents the policy, which is about connecting (already existing, local) object recognition to (already existing, local) established adulthood of the user.