Cars can already be stopped when stolen, it has been available for many years I think, it's not about Tesla or self-driving.

The new thing with some current and most future cars is that everything will be controlled by a computer that has software that is connected to internet and even Wi-Fi, which makes it prone to "computer hacks" we know so well.

From that point, the problems being faced come from both worlds: car world (stealing, accident, ...) and computer world (access to location or cameras, ransomware, ...).