Well I think banks have a few laws that prevent those things. But remembering the Pornhub incident where MasterCard and Visa stopped their partnership to strongarm them. In that case the motivation was child safety and not greed. But it was a display of power.
There are dealerships that install aftermarket devices in their cars.
There are tutorials on YouTube: How to start your car if it has been remotely turned off by the dealership.
It ranges between disconnecting the battery and starting the car before the device from the dealership has connected to how to find it under your dash.