A parking lot is a much denser cluster of delivery points than a neighborhood of three family houses and packages get stolen from locked cars less than from doorsteps (well maybe not in SF).
Edit: I'm not disagreeing about the creepy factor. This could be abused fairly easily. I expect that it's a matter of time before they sell access to the data set (which will probably include a picture of the license plate and the package sitting inside the car) to some authoritarian state (I'm betting PA, MA or TX) who will then mail a citation for every equipment violation they see. Building your own data set to do this wouldn't be worth it and wouldn't pass public scrutiny but when you can just buy someone's data set it's easy.
There's plenty of other legally white but ethically gray when done at scale things you could do with a data set that will likely include a smartphone-res picture of the interior of somone's car.
On the other hand. This opens up an option for people who live in one state but work in another to exploit differing laws to their advantage (tax, shipping restrictions)