In many San Francisco neighbourhoods, you are required to move your car every two hours to satisfy a parking restriction. However, in reality, you only need to move your car every two hours after it has been seen by an enforcement officer. John Naulty decided to use a Pi to detect when an enforcement officer was present. He uses the camera module and OpenCV to detect motion. The Pi then uploads the photograph to a website running Tensorflow which determines whether the movement is an enforcement vehicle or not and sends him a text if it is 75% sure. Naulty then has two hours to move his car from that point. Sneaky, eh? You can read a few quotes from Naulty and watch a video of him over at TechCrunch.