Social media has been awash with fake images of a stylish Pope Francis, Elon Musk protesting in New York and Donald Trump resisting arrest. Such AI-generated images and videos, or deepfakes, have become increasingly accessible due to advances in artificial intelligence. As more sophisticated fabricated images spread, it will become increasingly difficult for users to differentiate the real from the fake. Deepfakes get their name from the technology used to create them: deep-learning neural networks. When unleashed on a dataset, these algorithms learn patterns and can replicate them in novel — and convincing — ways. While this technology can be...