Apps and websites that use artificial intelligence to undress women in photos are soaring in popularity, according to researchers.

In September alone, 24 million people visited undressing websites, according to the social network analysis company Graphika.

Many of these undressing, or “nudify,” services use popular social networks for marketing, according to Graphika. For instance, since the beginning of this year, the number of links advertising undressing apps increased more than 2,400% on social media, including on X and Reddit, the researchers said. The services use AI to recreate an image so that the person is nude. Many of the services only work on women.

These apps are part of a worrying trend of non-consensual pornography being developed and distributed because of advances in artificial intelligence — a type of fabricated media known as deepfake pornography. Its proliferation runs into serious legal and ethical hurdles, as the images are often taken from social media and distributed without the consent, control or knowledge of the subject.