Although I'm pretty sure only the manufacturer has access to this data (as part of their copyright on the car), so it would take a warrant for law enforcement to get it. I don't have proof of that, but I would guess that's why you don't hear about it more. It's only used when absolutely necessary.
I was reading a recent insurance case where the driver staged and accident, but the black box indicated what really happened, and the driver withdrew the claim when presented with the evidence.
Widespread data logging including dash cams is going to improve driver behaviour. Even some cyclists are wearing 'dashcams' and this will no doubt improve treatment of all cyclists, even if overall penetration is low.
The ambiguity between automatic/automobile/autonomous really makes me hope a better word surfaces.
Self-driving car is a bit too long.
Maybe nowadays car will be demoted to semimobile, or Human Driven Car.