It’s a contractor’s. If it was a UPS branded truck they could reach out to UPS. In this case the only thing they seem to know is that the vehicle is in operatio

It’s a contractor’s. If it was a UPS branded truck they could reach out to UPS. In this case the only thing they seem to know is that the vehicle is in operation for Amazon. So they naturally must reach out to them. And Amazon should at the very least be able to tell which contractors they use in the area, or rather even which contractor delivered a specific package.