That's probably why it's not advertised. Because your car will tattle on you. I've often wondered about the black box in my car, if I were in an accident and I was going 71mph in a 70mph and they pulled by black box, would I be given a ticket even though I was not at fault?

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.

Precisely. Widespread knowledge would lead to tampering.

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.

I was also happy that some Police officers were wearing cams. 3rd eye is powerful.

Agreed. The issue when collecting data is that it's a rabbithole, you need to have a lot of data to avoid shallow judgement, and careful jurors too. Going at 71 (74,75) instead of 70 might turn against you, but if you have enough evidence that the other vehicle would have it you even at 70mph then the system will work.

This can be solved. Have all collected data be encrypted AND the owner of the car be the ONLY one with the decryption key.

This isn't the point, though. Even if people are afraid data may turn against them, they will never take the risk to use it.