Cameras in New South Wales, Australia will detect when drivers are using mobile phones. Importantly, the system has a human-in-the-loop which verifies the accuracy of the detection.
This kind of automatic policing raises concerns among many ethicists. (What if the system is bad at detecting certain races or genders and skews the enforcement?) But overall it is hard to find fault in this kind of efficient safety innovation. Innocent people are killed every day by distracted drivers.