Imagine this: You're on Reddit, or some forum, and you post under a pseudonym as your username. You think you're anonymous and no one knows you, so you can freely express your thoughts.
Well, a new study has just debunked that idea. It's called " Large - scale online deanonymization with LLMs," which is a fancy way of saying "discovering the real person behind a pseudonym."
Researchers from ETH Zurich and Anthropic, together with a research group called MATS, have demonstrated that today's powerful artificial intelligence chatbots can play the role of detective and reveal who is hiding behind a pseudonym.
How does it work;
Think of artificial intelligence as a detective. Only this detective is super fast and super smart. It has read every post ever written on the internet. Let's see how their system works in simple steps:
Reads and identifies clues: Artificial Intelligence looks at your posts and extracts little hints about you. Things that are part of your personality. Like it can see that this person talks a lot about coding games in Python, loves Marvel movies, complains about his school in Halandri, and types in a certain style.
He searches the entire internet: It checks LinkedIn, Google, other Reddit accounts, etc., to find potential real people who match these clues.
He thinks carefully and checks again: Artificial Intelligence thinks “Do these match? The writing style is the same, the hobbies align, the timing matches… yes, 90% of the time!”
The researchers named their method ESRC, which stands for Extract clues, Search, Reason, Calibrate.
Do you think this is all theory?
On real Hacker News users, the AI correctly matched a user's nickname to their real name 67% of the time, and when it made a guess, it was correct 90%. The paper also reports that matching the same person's Reddit posts from different years or groups had a success rate of up to 68%.
Scary? And the thing is, it only costs $4 to check on a person. Anyone with a good chatbot could do it.
One of the lead researchers, Simon Lermen, reported:
Can a team of smart researchers figure out who you are from your posts? If so, AI agents can probably do the same at a lower cost.
No more private life
Until now, staying hidden online was fairly easy because uncovering a pseudonym took hours or days for researchers. Now? One person (stalker, a company, or even a government) can uncover thousands of accounts very quickly.
This means that someone could find out your real name, school, city, or job from just a few comments. The old idea that “if I use a pseudonym, I’m safe” is no longer valid. We’ve reached the end of the practice of anonymity.
Welcome to a new 1984!
DOI: https://doi.org/10.48550/arXiv.2602.16800
Although the press releases will range from very select to rare, I said I'd pass...because sometimes the editors hide.
