Driverless Waymo cars in California briefly stopped on their own this week and quickly flagged teenage riders to police.
FOX 11 in Los Angeles said the cars caught illegal activity and hit the brakes.
The move sparked new questions from privacy groups about how Waymo handles what cameras inside store.
NPR aired similar concerns over constant passenger monitoring in Waymo rides.
Reason Magazine noted that anyone breaking the law inside Waymo vehicles should assume cameras to keep detailed records no matter what.
The incidents come as Waymo grows its service area and encounters more pricing reviews.