As the article says at the end, since this data is anonymized, it is only useful to see how people moved in general before shelter-in-place was implemented. You have to go full tracking on an individualized level to be really useful after that, like South Korea did/does. I wonder if this is the next step in the US and Europe. The next level after that is then requiring you carry a phone with the tracking app (or just set this up with the phone carriers behind the scenes) when you are outside your home. First as a temporary measure for this outbreak, of course, but always extended when it is about to expire, like the Patriot act. The potential for another outbreak will always be with us.

I personally would not like to live in such a country, but who knows if people would care enough to prevent it from happening.