Clearly the 'film only public spaces' argument is specious. It films everybody in their back yard, in their walled lot, in their private green space. It can't distinguish public from private from 10000 feet.

As I understand how its used, somebody robs a liquor store and drives away. Maybe 10 days later a detective gets a warrant for the footage from that day, finds the part where they drove away, then follows the footage backward to the part where they left their house. Then drives over and arrests them. Kind of like a time machine, or Minority Report in reverse.