>Sure, warrants aren't necessary, but the concept of mass, automated surveillance is so new that we simply haven't figured out what to do about it yet.
We haven't? It seems like we have: we're embracing it wholeheartedly. We're just careful to only use it (for now) on groups of people who don't have much power to push back on it.
Some people may disagree with it, but the society at large is doing this things, either led by or approved by our political leaders, whom most of the citizens elect.
