Let's say that you are driving along and a kid runs out in front of you, and you swerve to avoid them and you hit somebody else. You can be taken to court to answer for that decision. It might turn out that you haven't done anything wrong, but you can still be held accountable. But now let's say you weren't driving. Let's say that it was a self-driving car. In that case, the decision to swerve wasn't made in the moment, it was made months ago by whoever programmed it to perceive objects and have goals in the way that it does.
So called "autonomous systems" still do what they are told to do. They aren't really autonomous, they're just unsupervised. A person still has to tell it what its goal is, and how to gather and interpret the data that they use to achieve it. So if you get hit by a self-driving car, can you take the car company to court? 'Cause if not, then that company has just been given the unaccountable power of life and death over everybody who encounters their product.
