An AI-generated image of a city skyline and a mans face but AIs are unable to see bothZiqi Ding et al. (2025)Artificial intelligence programs can create optical illusions that other AIs are unable to recognise, creating a useful CAPTCHA test to differentiate humans from bots.A cat-and-mouse game has played outfor almost two decades between website developers who want to keep bots out of their sites and the hackers who want to bypass those protections. Websites have long deployed tests that are designed to be easy for humans to pass, but that trip up software.Read more