A deepfake is a video, audio or other content (e.g. image) that is completely or partially fabricated or created by manipulating existing, real content. Just as fake news calls into question the authenticity of real news, deepfake also calls into question the authenticity of real content. At the same time, deepfake has many advantages in addition to its often mentioned dangers. Following a historical overview of deepfake, the study describes these benefits and dangers, and then discusses possible legal responses after presenting tools for detecting deepfake.