And that's why we need to push our respective representatives to adopt laws that prohibit any kind of personal content scanning without a warrant. Personally, I would be ok if this scanning were applied to cloud-stored data that is shared to the public (e.g. social media platforms), but that's about it.

From the technical standpoint, Apple's implementation seems sound, although it does raise strong concerns about the future applications of the technology. Strong privacy laws can prevent abuse.