Deepfake technology enables anyone with a computer and an Internet connection to create realistic-looking photos and videos of people saying and doing things that they did not actually say or do. A combination of the phrases deep learning" and "fake", deepfakes first emerged on the Internet in late 2017, powered by an innovative new deep learning method known as generative adversarial networks (GANs). Several deepfake videos have gone viral recently, giving millions around the world their first taste of this new technology: President Obama using an expletive to describe President Trump, Mark Zuckerberg admitting that Facebook's true goal is to manipulate and exploit its users, Bill Hader morphing into Al Pacino on a late-night talk show. The technology is improving at a breathtaking pace. Experts predict that deepfakes will be indistinguishable from real images before long. It does not require much imagination to grasp the harm that could be done if entire populations can be shown fabricated videos that they believe are real. In a world where even some uncertainty exists as to whether such clips are authentic, the consequences could be catastrophic. In a recent report, The Brookings Institution grimly summed up the range of political and social dangers that deepfakes pose: "distorting democratic discourse; manipulating elections; eroding trust in institutions; weakening journalism; exacerbating social divisions ... and inflicting hard-to-repair damage on the reputation of prominent individuals."