PDF.
We show that large language models can be used to perform at-scale deanonymization. With full Internet access, our agent can re-identify Hacker News users and Anthropic Interviewer participants at high precision, given pseudonymous online profiles and conversations alone, matching what would take hours for a dedicated human investigator. We then design attacks for the closed-world setting. Given two databases of pseudonymous individuals, each containing unstructured text written by or about that individual, we implement a scalable attack pipeline that uses LLMs to: (1) extract identity-relevant features, (2) search for candidate matches via semantic embeddings, and (3) reason over top candidates to verify matches and reduce false positives. Compared to prior deanonymization work (e.g., on the Netflix prize) that required structured data or manual feature engineering, our approach works directly on raw user content across arbitrary platforms. We construct three datasets with known ground-truth data to evaluate our attacks. The first links Hacker News to LinkedIn profiles, using cross-platform references that appear in the profiles. Our second dataset matches users across Reddit movie discussion communities; and the third splits a single user's Reddit history in time to create two pseudonymous profiles to be matched. In each setting, LLM-based methods substantially outperform classical baselines, achieving up to 68% recall at 90% precision compared to near 0% for the best non-LLM method. Our results show that the practical obscurity protecting pseudonymous users online no longer holds and that threat models for online privacy need to be reconsidered.
Your adversaries right now...
haha, oh man. That actually reminds me. I know I mentioned the wiki thing - this is me: https://en.wikipedia.org/wiki/Beck_v._Eiland-Hall
Basically, back in 2009, I created glennbeckrapedandmurderedayounggirlin1990.com. It was largely in response to Glenn Beck's stupid technique of interviewing people - like to our first sitting Muslim member of Congress: "Now, I wouldn't say this, but some people are asking: Are you working for our enemies?" - to an elected member of Congress!
Of course, this was back in the Muslim-scare days after 9/11 still in 2009… and now we definitely have people in Congress working for our enemies.
But anyway. So the parody site.
My wife found a forum where some idiots were trying to track me down. I mean, my real name and address was out there, but they were looking for more information about me and the site. They were talking about what organizations must be funding this attack on their beloved Beck.
There was controversy at the time because an orgnization called ACORN was trying to get people to register to vote and supposedly signing up on behalf of people. IIRC the allegations were either bullshit or it wasn't a big deal or maybe it was and it was dealt with. All I remember for sure is that I thought it would be hilarious to offer these chucklefucks "evidence" for their conspiracies.
So I went out and copied the raw HTML from a 404 page on the ACORN website and made that the custom 404 page for my site. An then, to help these idiots "find" it, I made a "mistake" - I announced something on the main page and linked to a page that supposedly had the full story, only I intentionally put a typo in the link so the 404 page would come up. lol.
Oh, man, they went N U T S over in the forum "HOLY SHIT ITS ACORN BEHIND THIS" lolololol........
But anyway, your gif absolutely reminded me of those morons. That's how I envisioned their "hacking" of me. lol