For those interested; the best solution as far as I know for this kind of similarity detection is the Siamese network with RNNs in the first part. That implies you must extract fingerprints for all likely candidates (users) and then some to create a baseline. You can not simply claim that two users (adversary and postulated sock) are the same because they have edited the same page. It is quite unlikely a user will edit the same page with a sock puppet, when it is known that such a system is activated.
On Thu, Aug 6, 2020 at 10:49 PM John Erling Blad <[email protected]> wrote: > Nice idea! First time I wrote about this being possible was back in > 2008-ish. > > The problem is quite trivial, you use some observable feature to > fingerprint an adversary. The adversary can then game the system if the > observable feature can be somehow changed or modified. To avoid this the > observable features are usually chosen to be physical properties that can't > be easily changed. > > In this case the features are word and/or relations between words, and > then the question is “Can the adversary change the choice of words?” Yes he > can, because the choice of words is not an inherent physical property of > the user. In fact there are several programs that help users express > themselves in a more fluent way, and such systems will change the > observable features i.e. choice of words. The program will move the > observable features (the words) from one user-specific distribution to > another more program-specific distribution. You will observe the users a > priori to be different, but with the program they will be a posteriori more > similar. > > A real problem is your own poisoning of the training data. That happens > when you find some subject to be the same as your postulated one, and then > feed the information back into your training data. If you don't do that > your training data will start to rot because humans change over time. It is > bad anyway you do it. > > Even more fun is an adversary that knows what you are doing, and tries to > negate your detection algorithm, or even fool you into believing he is > someone else. It is after all nothing more than word count and statistics. > What will you do when someone edits a Wikipedia-page and your system tells > you “This revision is most likely written by Jimbo”? > > Several such programs exist, and I'm a bit perplexed that they are not in > more use among Wikipedia's editors. Some of them are more aggressive, and > can propose quite radical rewrites of the text. I use one of them, and it > is not the best, but still it corrects me all the time. > > I believe it would be better to create a system where users are internally > identified and externally authenticated. (The previous is biometric > identification, and must adhere to privacy laws.) > > On Thu, Aug 6, 2020 at 4:33 AM Amir Sarabadani <[email protected]> > wrote: > >> Hey, >> I have an ethical question that I couldn't answer yet and have been asking >> around but no definite answer yet so I'm asking it in a larger audience in >> hope of a solution. >> >> For almost a year now, I have been developing an NLP-based AI system to be >> able to catch sock puppets (two users pretending to be different but >> actually the same person). It's based on the way they speak. The way we >> speak is like a fingerprint and it's unique to us and it's really hard to >> forge or change on demand (unlike IP/UA), as the result if you apply some >> basic techniques in AI on Wikipedia discussions (which can be really >> lengthy, trust me), the datasets and sock puppets shine. >> >> Here's an example, I highly recommend looking at these graphs, I compared >> two pairs of users, one pair that are not sock puppets and the other is a >> pair of known socks (a user who got banned indefinitely but came back >> hidden under another username). [1][2] These graphs are based one of >> several aspects of this AI system. >> >> I have talked about this with WMF and other CUs to build and help us >> understand and catch socks. Especially the ones that have enough resources >> to change their IP/UA regularly (like sock farms, and/or UPEs) and also >> with the increase of mobile intern providers and the horrible way they >> assign IP to their users, this can get really handy in some SPI ("Sock >> puppet investigation") [3] cases. >> >> The problem is that this tool, while being built only on public >> information, actually has the power to expose legitimate sock puppets. >> People who live under oppressive governments and edit on sensitive topics. >> Disclosing such connections between two accounts can cost people their >> lives. >> >> So, this code is not going to be public, period. But we need to have this >> code in Wikimedia Cloud Services so people like CUs in other wikis be able >> to use it as a web-based tool instead of me running it for them upon >> request. But WMCS terms of use explicitly say code should never be >> closed-source and this is our principle. What should we do? I pay a >> corporate cloud provider for this and put such important code and data >> there? We amend the terms of use to have some exceptions like this one? >> >> The most plausible solution suggested so far (thanks Huji) is to have a >> shell of a code that would be useless without data, and keep the code that >> produces the data (out of dumps) closed (which is fine, running that code >> is not too hard even on enwiki) and update the data myself. This might be >> doable (which I'm around 30% sure, it still might expose too much) but it >> wouldn't cover future cases similar to mine and I think a more long-term >> solution is needed here. Also, it would reduce the bus factor to 1, and >> maintenance would be complicated. >> >> What should we do? >> >> Thanks >> [1] >> >> https://commons.wikimedia.org/wiki/File:Word_distributions_of_two_users_in_fawiki_1.png >> [2] >> >> https://commons.wikimedia.org/wiki/File:Word_distributions_of_two_users_in_fawiki_2.png >> [3] https://en.wikipedia.org/wiki/Wikipedia:SPI >> -- >> Amir (he/him) >> _______________________________________________ >> Wikitech-l mailing list >> [email protected] >> https://lists.wikimedia.org/mailman/listinfo/wikitech-l > > _______________________________________________ Wikitech-l mailing list [email protected] https://lists.wikimedia.org/mailman/listinfo/wikitech-l
