What’s a deepfake video? It uses the type of artificial intelligence system known as a “deep neural network” to study a large body of images of an individual and then synthesize new moving images based on the existing ones – in other words, to create video of that individual doing something she never actually did. Inevitably, deepfake videos of political candidates will appear, possibly as soon as this fall. How can we spot them? Prof. Siwei Lyu and two colleagues have worked out a way. (The headline above is not metaphorical.)