You're completely missing the point -- it's unfeasible, unpractical, and unproductive hitting millions of people on the head with $5 wrenches. This is the entire point -- they can do it easily with everyone now, they're not hitting people with wrenches -- that would invoke suspicion and retaliatory response that would curtail their legal powers to snoop around.
Maybe you're forgetting about the sorts of things that went on, are probably still going on, in various brutal military dictatorships around the world. Wrenches are just the start of what they do to people before they disappear them.
It isn't impossible to beat information out of millions of people. It's been done before and it'll be done again.
You say it'd invoke suspicion, but it wouldn't. If you're at the wrench phase of interrogation, you're already in a world where legal powers don't matter.
>Maybe you're forgetting about the sorts of things that went on, are probably still going on, in various brutal military dictatorships around the world
