3 ms·

> A sufficiently advanced algorithm will be able to find everything a person has ever posted online (by cross referencing, writing style, etc.) Is this like a

> A sufficiently advanced algorithm will be able to find everything a person has ever posted online (by cross referencing, writing style, etc.) Is this like a sufficiently smart compiler? :) Stylometry is well-studied. You'll be happy to know that it is only practical when there are few suspect authors for a post and each author has a significant amount of text to sample. So, tying a pseudonymous post back to an author where anyone and everybody is a potential suspect is totally infeasible in the vast majority of cases. In the few cases where it is practical, it only creates a weak signal for further investigation at best. You might enjoy the paper Adversarial Stylometry: Circumventing Authorship Recognition to Preserve Privacy and Anonymity by Greenstadt et al.

deleted 1y ago
[deleted]
sitkack 1y ago
Someone did a stylometry attack against hn awhile ago, it would with very high confidence unmask alt accounts on this site. It worked. There is zero reason to believe that it couldn't be applied on a grand scale.
- AStonesThrow 1y ago
  How do y’all prove it worked, O Privacy Wonks? How do y’all establish ye Theory Of Stylometry, O Phrenology Majors? O, @dang confirms it on Mastodon or something??
  - squeeeeeeem 1y ago
    It found 11 of my alt accounts with 90% accuracy. Now I make a new alt every post despite HN rules. sorry, but it is essential to do so.
    - nixgeek 1y ago
      Adding an extra “e” for each doesn’t create much extra mystery requiring stylometry to unmask you. More seriously, why is this essential?
      - schoen 1y ago
        > Adding an extra “e” for each doesn’t create much extra mystery requiring stylometry to unmask you. That language could be recognized by a deterministic finite automaton!
        AStonesThrow 1y ago
        How many "r"s are in "strawberrry"?
- noident 1y ago
  That sounds considerably more narrow than what the GP described. What if I don't have an alternate HN account? Or what if I do have one, but it has barely any posts? How can you tie this account back to my identity? Stylometry.net is down now, so it's hard to make any arguments about its effectiveness. There are fundamental limitations in the amount of information your writing style reveals.
  - FilosofumRex 1y ago
    Ted Kaczynski, the Unabomber, was identified from his writing style https://www.fbi.gov/history/famous-cases/unabomber https://www.fbi.gov/history/famous-cases/unabomber
    - BriggyDwiggs42 1y ago
      By his brother who he wrote loads of letters to, and with whom he discussed a lot of his ideological views. Very bad example.
    - wombatpm 1y ago
      It was a 28,000 word manifesto
- danaris 1y ago
  So, it found some alts. How do you know it didn't miss 10x more than it found? Like, that's almost definitionally unprovable.
  - jasonfarnon 1y ago
    I don't know about the original post being referenced, but the ground truth could be known to good approximation. I assume HN has a good idea of which accounts are the same person using IPs, and could actually evaluate the false negative rate.
fooker 1y ago
> that it is only practical You're missing the point, it doesn't have to be practical, only the illusion of it working is good enough. And if authoritarian governments believe it works well enough, they are happy to let a decent fraction of false positives fall through the cracks. See for example, polygraph tests being used in court.
- heylook 1y ago
  Exactly. The President of the United States held up a terribly photoshopped picture of some tattoos and claimed it clearly showed membership in MS13. Half the country immediately decided that was good enough proof for extrajudicial rendition. Authoritarians only care about a thin enough veneer of evidence to give them just enough cover with just enough people to get away with what they want and then move onto the next thing.
martin-t 1y ago
As others have pointed out, such algorithms written by amateurs have been demonstrated to work. You also assume people are meticulous in taking precautions and never make mistakes. People whose access to information is restricted (such as by the great firewall of china) won't even know stylometry exists. Even if it doesn't identify all cases, the chilling effect is enough. Authoritarians are not known for their attention to false positive rates. --- You didn't even try to address that dissent will be identified before it reaches a sufficiently conscious and intentional level to even consider taking precautions. Most people don't have alts for normal usage and tying an account to IP to real person is easy for the government. The only difficulty is identifying opponents at scale. --- Finally, please don't dismiss arguments by employing the "sufficiently snarky comment" technique.

deleted 1y ago

[deleted]

sitkack 1y ago

Someone did a stylometry attack against hn awhile ago, it would with very high confidence unmask alt accounts on this site. It worked. There is zero reason to believe that it couldn't be applied on a grand scale.

AStonesThrow 1y ago
How do y’all prove it worked, O Privacy Wonks? How do y’all establish ye Theory Of Stylometry, O Phrenology Majors? O, @dang confirms it on Mastodon or something??
- squeeeeeeem 1y ago
  It found 11 of my alt accounts with 90% accuracy. Now I make a new alt every post despite HN rules. sorry, but it is essential to do so.
  - nixgeek 1y ago
    Adding an extra “e” for each doesn’t create much extra mystery requiring stylometry to unmask you. More seriously, why is this essential?
    - schoen 1y ago
      > Adding an extra “e” for each doesn’t create much extra mystery requiring stylometry to unmask you. That language could be recognized by a deterministic finite automaton!
      - AStonesThrow 1y ago
        How many "r"s are in "strawberrry"?
noident 1y ago
That sounds considerably more narrow than what the GP described. What if I don't have an alternate HN account? Or what if I do have one, but it has barely any posts? How can you tie this account back to my identity? Stylometry.net is down now, so it's hard to make any arguments about its effectiveness. There are fundamental limitations in the amount of information your writing style reveals.
- FilosofumRex 1y ago
  Ted Kaczynski, the Unabomber, was identified from his writing style https://www.fbi.gov/history/famous-cases/unabomber https://www.fbi.gov/history/famous-cases/unabomber
  - BriggyDwiggs42 1y ago
    By his brother who he wrote loads of letters to, and with whom he discussed a lot of his ideological views. Very bad example.
  - wombatpm 1y ago
    It was a 28,000 word manifesto
danaris 1y ago
So, it found some alts. How do you know it didn't miss 10x more than it found? Like, that's almost definitionally unprovable.
- jasonfarnon 1y ago
  I don't know about the original post being referenced, but the ground truth could be known to good approximation. I assume HN has a good idea of which accounts are the same person using IPs, and could actually evaluate the false negative rate.

fooker 1y ago

> that it is only practical You're missing the point, it doesn't have to be practical, only the illusion of it working is good enough. And if authoritarian governments believe it works well enough, they are happy to let a decent fraction of false positives fall through the cracks. See for example, polygraph tests being used in court.

heylook 1y ago
Exactly. The President of the United States held up a terribly photoshopped picture of some tattoos and claimed it clearly showed membership in MS13. Half the country immediately decided that was good enough proof for extrajudicial rendition. Authoritarians only care about a thin enough veneer of evidence to give them just enough cover with just enough people to get away with what they want and then move onto the next thing.

martin-t 1y ago

As others have pointed out, such algorithms written by amateurs have been demonstrated to work. You also assume people are meticulous in taking precautions and never make mistakes. People whose access to information is restricted (such as by the great firewall of china) won't even know stylometry exists. Even if it doesn't identify all cases, the chilling effect is enough. Authoritarians are not known for their attention to false positive rates. --- You didn't even try to address that dissent will be identified before it reaches a sufficiently conscious and intentional level to even consider taking precautions. Most people don't have alts for normal usage and tying an account to IP to real person is easy for the government. The only difficulty is identifying opponents at scale. --- Finally, please don't dismiss arguments by employing the "sufficiently snarky comment" technique.