Hundreds of contractors working on a project for Meta were instructed to pose as minors online and probe how competitor chatbots responded to prompts involving suicide, sex, eating disorders, and other high-risk subjects, according to internal documents and five people familiar with the project. The prompts were often designed to push the chatbots toward responses their safety systems were supposed to refuse. A single round of testing completed in August 2025 saw more than 45,000 prompts run through the rival chatbots. The companies behind the chatbots weren't aware of the testing. Testing competitors' products is not, by itself, unusual in the artificial intelligence industry. Former contractors who worked on the project described several aspects as alarming. According to one former worker, employees feared the possibility they could be generating or preserving child sexual abuse material if a chatbot responded to certain sexual prompts involving minors. Another says they worried the project amounted to secretly taking material from competitors' systems to potentially feed back into Meta's system. While a dataset of thousands of youth-safety prompts could be useful for comparing how often chatbots refuse harmful requests, the scale and opacity of [this project, known internally as] Cannes, along with the lack of disclosure to the companies being tested, made it very different from other public safety benchmarks.