In the US, backup cameras are required to be included with the car to be sold. There is no law that I'm aware of that prevents people from disabling or removing them after the sale.
EDIT: I think I was incorrect. The law says "an altered vehicle that was completed on or after this date that was equipped with a rearview camera that already meets the new rearview requirements must continue to meet these requirements after the alterations."
https://www.camerasource.com/industry-news/understanding-new...
But I'm not sure how broadly that actually applies. So I don't know.
