That's not to say that we should give up fighting for some level of privacy even when we don't own the cars, but seems more likely that legislation would be passed that forces the vehicle owners/operators (Alphabet in the Waymo case) to blur peoples' faces. Then of course the state (police/gov/etc.) will clamor for a backdoor key that will unlock the blurred faces/bodies if a crime is suspected to have occurred. Speaking of, I wonder if Waymo already does blur people when they capture them through Waymo rides? I can't seem to find mention of it online.
This commentary assumes self-driving cars are here to stay and become the de facto way we drive instead of driving ourselves. Still not sure how their adoption plays out over time because, at least in the US, people will fight against mandates to use self-driving cars because it compromises their freedom (note that the freedom crowd (no judgment) will be saying that, at first, because they will consider it their right to drive themselves, but once the privacy implications are clear there will be full-on (figurative?) wars fought over self-driving). Guessing a politician, in Texas or another red state, will sooner than later enshrine the right-to-drive-oneself into the state constitution.