Thirteen words are enough for Cornell researchers to get a fake comment cited by AI agents trained on public forums. Brands that relied on Google rankings now have to learn to exist in chatbot answers: a far easier terrain to manipulate, where Reddit holds a central place.
The facts
- The r/poisonai subreddit, with 100,000 members, deliberately publishes false stories to observe how Google AI and ChatGPT pick them up.
- On r/Biohackers, moderators now remove more than half of all posts, against less than 10% previously.
- Reddit has been selling access to its content to Google and OpenAI since 2024, while suing Anthropic for unauthorised use.
Why does Reddit carry so much weight in AI answers?
Generative engines look for content perceived as authentic: first-hand experience, discussions, opinions from real users. That is exactly what Reddit concentrates, and since the platform began selling access to its content to Google and OpenAI, those discussions feed directly into the answers your prospects read. A brand recommendation in a Reddit thread can end up, word for word, in a ChatGPT answer.
The Cornell experiment shows the flip side of that mechanism: if thirteen well-placed words are enough to get an AI agent to repeat false information, then the channel can be manipulated, and it will be. The communities' reaction is already visible: moderation rates multiplied by five on some subreddits, and experiments such as r/poisonai documenting the flaw live. For a brand, the temptation to plant disguised messages there is real; it is also the shortest route to a ban and a damaged reputation, because such manipulation ends up being detected, by moderators and by AI platforms alike.
AIxH's view
Twenty years of Google SEO do not teach you how to exist in an AI answer: the sources, the criteria and the risks are different. It is ground we watch closely for our GEO (generative engine optimisation) clients, within our SEO & GEO service: tracking the sources each engine actually cites, an authentic presence in the communities that matter, and never any manipulation, which remains the surest way to disappear from the answers.