Yeah, both these points!
I don't like the precedent this sets, and it could certainly be used for bad things down the road. (For example, maybe knowing when people come into contact with one another is great for pandemics, but not so great 'underground' meetings of a persecuted group.)
But, as pointed out, if it is the government you fear (quite reasonably, IMO), you're already in deep dodo by just having a cell phone. Your rough location is constantly being tracked, and I'm sure your friendly telco would be more than happy to turn that info over to the gov't along with your call records and such.
This is a bit better data, I suppose, especially if combined. But, there are bigger concerns already commonplace.
Oh, and I should probably point out that my issue with it is more that by the time they get it working, the need for it will be mostly gone. And, even if it does work well (and assuming it is needed), I don't think this things was really on a scale to warrant such efforts anyway. It's like throwing a bucket of water on a burning building and being all happy with yourself.