Facebook messages being used to arrest women for abortions.

That's a misrepresentation of what happened. The police already suspected her, and so they requested the information from Facebook. Facebook didn't voluntarily supply a bunch of data to the police for no reason, and then the police didn't comb through all the data to find this one crime that they otherwise didn't know about.

What is being suggested with the automatic cars is that the police are actively monitoring the surveillance footage looking for criminal activity. They definitely won't be doing that. It's way to much like work.