A software developer has created a website that generates fake faces, using artificial intelligence (AI).
Thispersondoesnotexist.com generates a new lifelike image each time the page is refreshed, using technology developed by chipmaker Nvidia.
Some visitors to the website say they have been amazed by the convincing nature of some of the fakes, although others are more clearly artificial.
And many of them have gone on to post some of the fake faces on social media.
Nvidia developed a pair of adversarial AI programs to create and then critique the images, in 2017.
The company later made these programs open source, meaning they are publicly accessible.
As the quality of synthetic speech, text and imagery improves, researchers are encountering ethical dilemmas about whether to share their work.
Last week, the Elon Musk backed OpenAI research group announced it had created an artificially intelligent "writer".
But the San Francisco group took the unusual step of not releasing the technology behind the project publicly.
"It's clear that the ability to generate synthetic text that is conditioned on specific subjects has the potential for significant abuse," the group said in a statement to AI blog Synced.