Large-Scale Online Deanonymization with LLMs • Hacker News Board

Re: Large-Scale Online Deanonymization with LLMs

#151

Post by SchemaLoad » Wed, Feb 25, 2026, 10:38 PM UTC

slopinthebag wrote: post #105

danielodievich wrote: post #88

I post under my real name here, pretty much the only place I post. It keeps me honest and straight in what I say when I choose to say it. I tried talking to my children about leaving as clean of a footprint on the internet as one can in anticipation of future people/systems taking that into consideration. I don't know what it will be but I would expect some adversarial stuff. Trying to keep clean is what I'd prefer f…

I think as the younger generations come of age they simply will not care about that sort of thing. Like it or not, it's part of the culture and might just be accepted as the norm.

I think it's kind of happened already. All the time we see news of politicians or famous people having their very old photos, comments, or reddit accounts found with distasteful takes. And it seems they can mostly just handwave it away with "Hey that was 10 years ago and I wouldn't make those comments today" and nothing seems to come of it.

Re: Large-Scale Online Deanonymization with LLMs

#152

Post by SchemaLoad » Wed, Feb 25, 2026, 10:41 PM UTC

Jerrrrrrrry wrote: post #98

john_strinlai wrote: post #48

many people tend to overlook how little information is needed for successful de-anonymization. i like to introduce students to de-anonymization with an old paper "Robust De-anonymization of Large Sparse Datasets" published in the ancient history of 2008 ( https://www.cs.cornell.edu/~shmat/shmat_oak08netflix.pdf ): " We apply our de-anonymization methodology to the Netflix Prize dataset, which contains anonymous movie…

Throwaway accounts using "clever" turns of phrase can often be anonymized by double click, right-clicking -> googling their witty pun and seeing their the sole instance elsewhere, on Twitter, Facebook, etc If I see a couple words I dont know in a row, I can infer a posters real name. Id be more specific but any example is doxxing, literally so

If you have access to the whole site dataset it's much more reliable with simpler checks. You can just use word usage frequency of common words. Someone posted a demo here of doing this to HN comments which was very effective at showing alt accounts for a user.

Re: Large-Scale Online Deanonymization with LLMs

#153

Post by SchemaLoad » Wed, Feb 25, 2026, 10:44 PM UTC

wasmainiac wrote: post #148

Could another mitigation be polluting identities online with fake ones so that real identities become hard to sift out. For example if I tell my bot to clone me 100x times on all my platforms, all with different facts or attributes, suddenly the real me becomes a lot harder to select. Or any attribute of mine at all becomes harder to corroborate. I hate to use this reference, but like the citadel from Rick and Morty.

Probably, but it also be the complete destruction of social media when there are 100 spam bots for every real person.

Re: Large-Scale Online Deanonymization with LLMs

#154

Post by deadbabe » Wed, Feb 25, 2026, 10:50 PM UTC

Doesn’t all this deanonymization stuff depend on one fatal assumption: that people are actually being truthful with what they say about themselves?

If you’re basically LARPing a new personality every time and just making up details about where you live or what your life is like then how is this ever going to work? Someone could say they live in San Francisco while actually living in Indiana.

Re: Large-Scale Online Deanonymization with LLMs

#155

Post by croes » Wed, Feb 25, 2026, 10:55 PM UTC

danielodievich wrote: post #88

I post under my real name here, pretty much the only place I post. It keeps me honest and straight in what I say when I choose to say it. I tried talking to my children about leaving as clean of a footprint on the internet as one can in anticipation of future people/systems taking that into consideration. I don't know what it will be but I would expect some adversarial stuff. Trying to keep clean is what I'd prefer f…

> I tried talking to my children about leaving as clean of a footprint on the internet as one can in anticipation of future people/systems taking that into consideration.

You don’t know what information about you can bring you in trouble in the future.

Re: Large-Scale Online Deanonymization with LLMs

#156

Post by prats226 » Wed, Feb 25, 2026, 10:56 PM UTC

If with LLM's you can deanonymize at scale, on a personal level, you should also be able to figure out what posts are leading to this deanonymization and remove them or modify them.

Re: Large-Scale Online Deanonymization with LLMs

#157

Post by notepad0x90 » Wed, Feb 25, 2026, 11:00 PM UTC

Even without LLMs this was possible.

But with HN, I'd like to ask @dang and HN leadership to support deleting messages, or making them private (requiring an HN account to see your posts).

At first I thought of how this would impact employment. But then I thought about how ICE has been tapping reddit,facebook and other services to monitor dissenters. The whole orwellian concern is no longer theoretical. I personally fear physical violence from my government, as a result. But I will continue to criticize them, I just wish it wasn't so easy for them to retaliate.

Re: Large-Scale Online Deanonymization with LLMs

#158

Post by croes » Wed, Feb 25, 2026, 11:02 PM UTC

gambutin wrote: post #142

danielodievich wrote: post #88

I post under my real name here, pretty much the only place I post. It keeps me honest and straight in what I say when I choose to say it. I tried talking to my children about leaving as clean of a footprint on the internet as one can in anticipation of future people/systems taking that into consideration. I don't know what it will be but I would expect some adversarial stuff. Trying to keep clean is what I'd prefer f…

How would "flooding the zone" actually work in that case? AFAIK the strategy is usually used to divert attention from one subject that could be harmful to a person to some other stuff. Wouldn’t spamming in that case provide more information about you?

If in one post you say you’re Jewish, in the next you are Christian, in the next your Hindu, in the next youre Atheist it’s harder to know what your really are.

You could even mislead people if you know the difference between your and you‘re.

Re: Large-Scale Online Deanonymization with LLMs

#159

Post by albumen » Wed, Feb 25, 2026, 11:02 PM UTC

JohnMakin wrote: post #147

NetOpWibby wrote: post #126

Earlier quoted context omitted.

> I operate by a simple, general rule - I don't often say anything online I wouldn't say directly to someone's face in real life. More people should keep this same energy. I try to stress this to my kids and it feels like it's falling on deaf ears in regards to my teen. Alas.

I can be a rude prick online sometimes, but I can be in real life too - basically though the reason I do this is I never want it to be some huge surprise IRL if someone sees what I write online and be like, "wow, I didn't know that about him." I'm pretty much what I am online and IRL the same. For some reason this seems to matter for me, at least in the past when people have tried to like, send employers stuff I may…

Your framing is interesting. You may feel that you can’t change who you are in real life, but people have a choice on how they behave online (or choose not to engage at all). So you could choose to be nice (or at least not a jerk); I’m pretty sure you wouldn’t get people writing to your employer complaining. I’d argue that if you know you’re sometimes a jerk, it’d be less stressful for you and others if you didn’t bring that energy online.

Re: Large-Scale Online Deanonymization with LLMs

#160

Post by iamnothere » Wed, Feb 25, 2026, 11:03 PM UTC

angry_octet wrote: post #141

iamnothere wrote: post #129

Despite being pseudonymous, I don’t take great pains to hide who I am. I am in my 50s and live on the West coast. I don’t have socials and I don’t post anywhere else. Have at it! If you are semi-retired, you’re free from the threat of cancellation. As long as you aren’t posting about crimes, there’s limits to what anyone can legally do to you. (Still, it’s good to be prudent and limit sharing.)

Unless you're in the nebulous situation of being Hispanic in the US, in which case you might get profiled. Or you might have family with jobs that are subject to pressure -- and right now, that seems like most jobs, because calling employers spineless is an insult to worms. Or if you'd like to travel by air, because watchlists are back, and carriers may just refuse service.

Fair enough. I am in a category that’s typically lower risk (though not zero) for profiling, so sometimes I forget that. Still, the potential risk isn’t a good reason to silence your voice if there are issues that you find important. The best defense is to avoid giving out personal details and avoid discussion on non-pseudonymous social sites.