Because otherwise your Waymo might “snitch” to the cops, as in the case of two 15-year-olds in California. According to 404 Media, the two teens were detained after the robotaxi company reported them for drinking and shooting Orbeez from the vehicle. Seems like the kind of behavior you may invite when you open up your unsupervised ridehailing service to the underage. But also Waymos are covered in cameras, inside and out, and have been known to report wrongdoing to the cops. Basically they’re roving surveillance machines!