It's not yet concerning since you need to hardwire to the custom serial bus of modern car to have access to steering and cruise control systems. What's concerning is the trend started by Tesla that remotely disables your car.
It would be quite concerning if they disabled cars based by “our automated systems detected breach of community rules” without ability to dispute it in future.
Right now disabling car after violent crash looks like obvious security feature that every car (especially electric).
