Are you aware of BART Police or MTA Police? All trains have conductors who monitor passenger behavior and enforce rules/laws.
How about things taking place outside the car?
Can Waymo mount a robotic machine gun next to the LIDAR and snipe suspected terrorists? Release tear gas? Self destruct, killing several nuns to protect s CEO?
Btw ghost guns are not all instantly illegal.
I am not against monitoring for safety - I am against deploying a sophisticated network of automated monitoring that covers all digital and soon physical aspects of my life for my "safety" by for profit companies.
Unfortunately taking someone somewhere to rob or assault them doesn’t look that different from taking a drunk friend to a safe place.