Researchers from the University of Zurich secretly ran a months-long AI experiment on Reddit’s 3.8M-member r/changemyview community without user consent.
A gaggle of researchers from the University of Zurich ran a covert months-long experiment using AI-generated comments to influence Reddit users without their knowledge or consent.
The experiment took place on r/changemyview, a 3.8M-member subreddit known for civil debate. The researchers deployed large language models (LLMs) to put in writing personalized, persuasive replies, posing as real people, to see if AI could change users’ views.
The details
- AI-generated comments, posing as real users, were posted to sway opinions.
- Personas included trauma survivors and controversial political voices.
- The AI used personal data scraped from users’ histories to tailor persuasive replies.
- None of the activity was disclosed, violating subreddit and Reddit-wide rules.
This wasn’t nearly bots.
It was psychological manipulation using personal data to check how effective AI might be at changing people’s minds.
Reddit’s Chief Legal Officer Ben Lee called it “deeply unsuitable on each an ethical and legal level” and confirmed that Reddit is preparing formal legal motion.
Photo by Brett Jordan on Unsplash
The researchers’ defense
They claim their ethics board approved the project and argue their goal was to point out how AI may very well be misused to control elections or spread hate speech.
“We consider the potential advantages of this research substantially outweigh its risks,” the researchers wrote.
The backlash
Mods of r/changemyview were outraged, calling the research “unwelcome” and “manipulative.”
They’ve filed a grievance and asked the university to dam publication of the study. This experiment reveals a growing threat: AI-powered persuasion at scale, without consent. It shows how easily people might be influenced when AI knows your beliefs and may mimic your peers.
Redditors were used as test subjects.
This wasn’t just an instructional exercise. It shows how powerful and subtle AI manipulation might be, especially when it mimics trusted human voices using personal data.
With generative AI becoming widespread, the chance of AI-driven manipulation isn’t any longer theoretical. It’s real, and it just happened on one among the web’s biggest communities.
Now Reddit, one among the world’s largest online communities, is fighting back.
