cross-posted from: https://lemmygrad.ml/post/10899106

AI Can Now Easily Unmask Your Secret Online Life for $4

A new research paper from ETH Zurich, Anthropic, and MATS demonstrates that Large Language Models can automatically de-anonymize users across platforms like Reddit and Hacker News.​

The AI acts like a digital detective using a method called ESRC (Extract, Search, Reason, Calibrate). It scans a user’s post history for subtle clues (hobbies, writing style, locations), searches the wider internet (LinkedIn, other forums) for matches, and uses complex reasoning to confirm the identity.​

The terrifying results:

• It correctly linked secret Hacker News usernames to real people 67% of the time (with 90% accuracy when it made a firm guess).​
• It successfully matched a person’s separate Reddit accounts from different years 68% of the time.​
• The entire automated process costs only $4 per target.​

“Practical obscurity”-the idea that you’re safe online because it takes too much human effort to connect your digital breadcrumbs-is dead. Anyone with a few dollars and an LLM API can now mass-dox thousands of pseudonymous accounts in minutes.