and someone following too closely and not paying good attention to you (and without auto-braking)
to collide with you in the rear. Presumably the occurrence of that would be less than the number of
accidents prevented by auto-braking.

But I would doubt it happens very often if at all.

These systems only kick in when the driver should already have started braking, but isn't. In theory a good driver could operate a vehicle equipped with this for years and not even know it, since it is never given cause to activate.

Sometimes it's scary as hell when it does, because my car decelerates. It's a real problem when I'm driving over a bad patch of asphalt on an onramp and it kicks on while I need to accelerate rather than decelerate, for example.

If the same geniuses at Ford get to design a system that can stop a car entirely? People are definitely going to be killed.

Just set the cruise control and the car automatically adjusts speeds to maintain a safe distance between the car in front of you.

For collision avoidance the car provides you with a collision alert before automatic braking is applied.

There have been a few times when swerving has saved me.

My car is 22 years old, and runs very well...I am keeping it. Al this loss of control over driving un-nerves me.

so you still have steering authority over the vehicle

There's not much data yet on their effectiveness because very few cars have it. The DOT and IIHS are already convinced enough to make it mandatory by 2022.

This is a common reaction to innovation.