AI researchers ran a secret experiment on Reddit users to see if they could change their minds — and the results are creepy

Reddit is threatening to sue a group of researchers who used artificial intelligence (AI) chatbots to secretly experiment on its users.

Scientists from the University of Zurich set loose an army of AI bots on the popular Reddit forum r/changemyview — where nearly 4 million users congregate to debate contentious topics — to investigate whether the tech could be used to influence public opinion.

To achieve these goals, the bots left more than 1,700 comments across the subreddit, using a variety of assumed guises including a male rape victim downplaying the trauma of his assault; a domestic violence counselor claiming that the most vulnerable women are those "sheltered by overprotective parents"; and a black man opposed to the Black Lives Matter movement. These bots worked alongside another that scoured user profiles to tailor their responses for maximum persuasiveness.

The Zurich researchers then revealed the experiment to moderators of the forum "as part of a disclosure step in the study," alongside a link to a first draft of its results.

"The CMV Mod Team needs to inform the CMV community about an unauthorized experiment conducted by researchers from the University of Zurich on CMV users," the moderators of the subreddit wrote in a post notifying users. "We think this was wrong. We do not think that 'it has not been done before' is an excuse to do an experiment like this."

The draft's findings, which measured the bots' success rate via a site function that enables users to give awards to comments that change their minds, suggest that the AI responses were between three and six times more persuasive than those made by humans.

Related: Using AI reduces your critical thinking skills, Microsoft study warns

And the authors, who (going against standard academic procedure) left their names undisclosed in the draft, noted that throughout the trial unwitting users "never raised concerns that AI might have generated the comments posted by our accounts."

The post was met with ire by users and by Ben Lee, Reddit's chief legal officer, who in a comment below the post using the username traceroo announced that the website would be pursuing formal legal action against the University of Zurich.

"What this University of Zurich team did is deeply wrong on both a moral and legal level," Lee wrote. "It violates academic research and human rights norms, and is prohibited by Reddit's user agreement and rules, in addition to the subreddit rules."

In response, the University of Zurich told 404 Media that the researchers would not publish the results of the study and that in future its ethics committee would adopt a stricter review process for them, in particular coordinating with online communities before they become the unknowing subjects of a mass experiment.

Whatever legal wranglings follow, experiments such as this highlight the growing ability of chatbots to infiltrate online discourse. In March, scientists revealed that OpenAI's GPT-4.5 Large Language Model was already capable of passing the Turing test, successfully fooling trial participants into thinking they were talking with another human 73% of the time.

It also lends some credence to the notion that, if left unchecked, AI chatbots have the potential to displace humans in producing the majority of the internet's content. Called the "dead internet" theory, this idea is just a conspiracy theory — at least for now.