Smile for the camera — or machines will do it for you. Twitter bot Smile Vector uses artificial intelligence to make celebrity photos smile. Similar technology can make 3-D models from 2-D images, manipulate facial expressions in real-time video, or generate sound based on silent footage. Now machines trained on photo databases can generate their own convincing images, which could benefit would-be hoax artists. These technologies have huge ramifications for fake news, when a faux video of a president speaking could look convincing — and go viral.