We might be talking past each other. You're talking purely legal interpretation, I'm talking society and philosophy.

My point is that government cannot be trusted to have this kind of power because it will at some point be turned against the population when dissent threatens the people holding power; it is inevitable. The least we should do is make laws strictly controlling access and purpose of access to such tools for criminal investigations, but I don't think that's enough to stop abuse and civil oppression.