cross-posted from: https://lemmy.world/post/49778353

Also /c/modabuse. Also /c/yepowertrippinbastards. Also lemmy.ml/c/worldnews, comrade, ACAB, and 552 individual accounts across 67 instances, about half of them on lemmy.world.

None of this is in the source code. It's downloaded at runtime from a file nobody has ever looked at.

If you're just tuning in

Tesseract is a third-party web frontend for Lemmy, maintained by asimons04 and licensed AGPL-3.0. Admins deploy it on their own servers alongside or instead of lemmy-ui, and there are public instances of it people use to browse Lemmy generally. If you've used a Lemmy site that didn't look like stock Lemmy, there's a fair chance it was this.

Last week db0 posted a PSA: Tesseract contains a blacklist of instance domains compiled directly into the application. 32 of them. Admins can't see it, can't configure it, and aren't told it's there. Connect to a listed instance and the app tells you it's "incompatible," which is not true.

I went through the code to see how that was implemented. The hardcoded list turns out to be the small half of the system.

There's a second filter policy fetched over HTTP every time the app loads. It isn't in the git repository. It's unauthenticated and world-readable, so anyone can pull it. Right now it carries 552 user accounts, 2,275 username patterns, 54 instances, 97 communities, 289 keyword patterns and 351 domains, with every category set to hide matches rather than flag them. Not collapsed behind a click. Simply absent, with no indication anything was removed.

Verify all of it in ten seconds

curl -s https://tesseract.dubvee.org/tesseract/api/system/policy \
  | base64 -d | gunzip > policy.json

That's the live policy, base64-wrapped gzip, 111KB of JSON when it unpacks. There's a stale fallback copy at /data/policy.dat as well.

It filters criticism of moderators

• lemmy.sdf.org/c/modabuse — listed
• lemmy.dbzer0.com/c/yepowertrippinbastards — listed
• lemmy.dbzer0.com/c/YPTBcirclejerk — listed
• community regex power ?tripping?
• keyword censoring me

Call the rest of it whatever you like. This part is not spam defence.

It filters words

The 32 community name patterns include Communis(t|m), Conservativ(e|es|ism), Leftis(t|m), Libertarian(ism)?, ^Green Part(y|ies), Zionis(t|m), (Police|Cops), guillotine and billionaire.

Keywords include comrade, ACAB, neoliberal, proletaria(n|t) and death to.

Filtered communities on instances that aren't blocked: lemmy.ml/c/worldnews, lemmy.today/c/news, lemmy.ca/c/politicalnewscanada, lemmy.ca/c/usa, infosec.pub/c/strategic_unions.

The 552 users aren't bots

67 instances. 272 on lemmy.world alone, 40 on sh.itjust.works, 19 on lemmy.ca, and 28 instances contributing exactly one person each.

355 of the 552 usernames are plain alphabetic, twelve characters or under, median length eight. Only 36 look like spam registrations. A bot list looks like the opposite of that.

Seven of them aren't even Lemmy. There are Mastodon and Friendica accounts in there: people who have never used Lemmy, hidden by a Lemmy frontend, with no possible way of finding out.

I have the list and I'm not posting it. Most of these are ordinary people who got pattern-matched, and 552 names on this comm is a harassment target inside an hour. Run the command above and grep for yourself.

And it lies about it

When the instance block fires you get: "Incompatible Instance. Not Supported. $instance is not compatible with Tesseract."

Nothing is incompatible. It's a policy decision dressed as an API error, and it's what had db0 chasing a version mismatch that never existed.

For the hidden users, communities and keywords, you get no message at all.

Admins can't switch it off

Tesseract has env vars for PUBLIC_DOMAIN_BLACKLIST, PUBLIC_FAKE_NEWS_BLACKLIST and the shortener lists. There is none for either blocklist. enableToxicMode bypasses the other filters and explicitly not this one.

Self-host it and you cannot disable this, nothing in your config admits it exists, and the contents can change without you pulling a commit.

Before someone says it

A lot of that domain list is real spam defence. It filters conservatism as well as communism. "It targets the left" doesn't survive the data and I'm not going to pretend it does.

The problem is that spam filtering and political editorial got welded into one undocumented, remotely-updatable blob, shipped hidden, to admins who've never read it and users who don't know it's there. The spam work is what makes the rest unauditable: "it's a spam list" answers every individual question and none of the whole.

And /c/modabuse is not spam.

Asks

1. Publish the runtime policy in the repo, or kill the endpoint.
2. Stop reporting a policy block as a technical incompatibility.
3. Tell users when something's been hidden. One line.
4. Give operators an off switch, like every other blacklist in the codebase has.

It's AGPL-3.0 and db0 already forked it. That's the licence working as designed. But forking isn't disclosure, and the admins who need this are precisely the ones with no reason to go looking.

If you run Tesseract, you are relaying a 111KB moderation policy you have never read, under your instance's name, to users who don't know it exists.

Full contents of every list, unedited, in the comments.

Damn, that's pretty wild

Hilarious. Well, I never used Tesseract, but now I'll make sure never to recommend it

This tells me the project cannot be trusted at all. The dev is clearly willing to ship undisclosed block lists... What's next, a crypto miner? Credential harvesting? Who knows.

I took a look at it earlier today and the addition of instances to be blocked was super shady and sloppy on part of the maintainer. Some high profile instances were added to the blocklist alongside unrelated changes and not mentioned in the git commit message, for example this commit: https://github.com/asimons04/tesseract/commit/fcd71e01e9f64d5ff40dbee9b815971bc00e9a2a

Also apparently the error you'd get when going to the blocked instance was a generic error which makes the user think there's a network issue or incompatibility with the API or something and the idea of a hard coded blocklist is never presented to the user as the source of the issue.

Yeah that's what I was thinking. I wonder what his track record on open source is.

I do sort of appreciate the irony on this one, but in general fuck this dev.

fwiw I'd recommend photon, it's fantastic and the dev seems to work really hard on it. Hope they aren't doing something shady either!

This is very upsetting. I could see an argument if it was made a user toggle for a "more friendly experience" or something like that (Like the enable toxic mode toggle), but hiding the blacklist and then an opaque error message is cowardly. Having it be pulled every time from another website instead of built into the software is also a very clear accountability dodge.

Also reading over the file, I think it's biased, especially towards unfairly heavy moderation.

Edit: Just noticed I'm on the blocklist. What he said fuck me for?

This dude just looks like he's building a fediverse he wants to see?

How does a forum with such few users have so much drama?

Libs love betrayal and being evil for no fucking reason.

Never trust anything defiled by shitlib hands.

It's just liberalism. The whole thing is just doing liberalism.

Some high profile instances were added to the blocklist alongside unrelated changes and not mentioned in the git commit message… Also apparently the error you'd get when going to the blocked instance was a generic error…

Yeah, the combination of those two issues are exactly why the hidden blocklist was noticed in the first place. The site admin for db0 noticed that their frontend was broken after they updated their Lemmy stack. But the “incompatible” version of Lemmy they had just updated to was supported. So what was causing the incompatibility? Maybe an API issue? Nope, API is fine.

After some digging, they eventually realized that it was happening due to an instance block at the frontend’s level. But they didn’t have their own instance blocked in the frontend, so why was it being blocked? Turns out, it was because they were previously running an old version of Tesseract from before the blocklist was implemented. When they updated their stack (which also updated Tesseract), the new version suddenly included the hidden blocklist code. So when they tried to start their stack after updating, the new version of Tesseract quietly downloaded the hidden blocklist (which can’t be disabled) and blocked the instance it was currently running on. This effectively broke the frontend for db0, which is what led to the investigation and subsequent hidden blocklist discovery.

This is the beauty and downside to open source. Anybody can force their political views in their software. But once discovered, it can be forked and fixed.

It’s a shame that everything has become so politicized that people feel the need to shove their religious political beliefs down everyone else’s throats. Yeah, we all know who the Bad Guys(TM) are; we don’t need to be constantly reminded.

Give users their voices back (or at least choice in what they want to see and block). It’s the decent thing to do. Anything else makes you a certified asshole.

I said what I said.

Why do you keep repeating this throughout these comments chief?

Being self important is not a political act and so far there is no indication of a political motivation, just that the dev somehow got the idea of appointing themselves secret online discourse admin. If it turns out there is some financial goal behind it i'm with you tho.

The developer behind Tesseract is the same user who has displayed the habit of preemptively banning users who have never participated in or even visited his communities, particularly those that were on dubvee.org. Apparently for ideological reasons, or simply for being associated with a particular Lemmy instance.

So at the risk of stirring up even more Fediverse drama by saying it, it seems like the findings above are squarely on brand.

Not to come over all Graham Chapman about it or anything, but I always found that type of behavior to be very silly.

Edit!

I got curious and pulled down the data to have a look. If you want to do this on Windows (don't @ me about it, alright?)

Anyway, guess what! I'm on the list. I'm a celebrity, ma! I ought to be on TV.

Thanks to the GOAT who found this!

Then run an instance, Beehaw style.

Is your account just for this sort of trolling? I'd hate to think you were being honest, but trolls tend to be a tiny bit subtler.

It looks like there is an 'enable toxic mode' setting that DOES switch off the auto-updating blocklist. The LLM that wrote this post claimed that there is no way to turn it off.

from src/lib/policies/system.ts:

export async function updateSystemFilterPolicy() {  
    if (SBDisabled && get(userSettings).enableToxicMode) {  
        SYSTEM_POLICY.set(BLANK_SYSTEM_FILTER_POLICY)  
        return  
    }  
   // auto-update of blocklist continues below  

The original post was written using AI so it's going to have a lot of inaccuracies like that.

Overall though, having gone through the code myself, the LLM is in the right ballpark. The most friendly evaluation I can give is that this does seem poorly documented, too opaque and overly prescriptive. And needlessly encrypting the payload looks very shifty.

Lol, I made the list. Didn't this admin have a big ol' crashout and "retire" some time ago?

Yeah it's the trans people who simply want to exist who are toxic

Edit: no indication any of that post was LLM, but would love to hear why you think that.

Though I suspect that's just a tactic to get people to shift their ire.

it's not my job to moderate the fediverse, you won't need to worry about seeing any of this in photon

So a system named after a hypothetical, hyper-dimensional solid turns out to have hidden depths, secret facets that we can't see from our universe?

Don't care about your ideological bent, engaging this clearly in bad faith with the fediverse should be unwelcome here.

Its blatantly dishonest. That is unacceptable; this project and the people building it should have no home here.

Right?? I expect this kind of crap on reddit, but Lemmy? Really?

being self important is not a political act

Citation needed.

financial goal

I didn't say capitalism I said liberalism.

No I just have a grudge against unselfaware cryptofascists. Personal stuff.

Any particular reason people aren't forking it and adding whatever elements to the shitty dev keeps locking it out?

Not because the product is good or anything. But more of a big fuck you to the dev as this new version gets all of their hard work too.

is that you @Deceptichum@quokk.au ?

Yes, I am another user on the same server. Thank you for noticing. My reasons for doing this shall remain inscrutable.

Liberalism = Liberty

so you hate liberty?

I think we just notice it more because we have less content, so you're more likely to hear about each bit of drama that comes up and you're more likely to know one of the parties involved. There was lots of drama on reddit too, but I didn't subscribe to the communities that talked about it and I often didn't know enough about each incident to judge anyone

It's still annoying though 🫤

appreciate it :)

There are a few solid ones there. Photon and Blorp are my personal favourites on desktop

https://fedecan.ca/en/guide/threadiverse/alternative-uis

Well this is also what the offending dev accuses some mods. I would love to join your stone throwing, but i also think there are some truths. Libs and Commies and Queers all can react overly hostile and not seldomly react disproportionate (all 3 of them, not every last queer person).
Aaand i think the dev is butt hurt, but if he chooses an unreasonable way to react we can be glad to leverage FOSS.

I'll gladly take the downvotes of shame for my previous comment on another thread. Tesseract dev has gone looney

The thing is Lemmy is populated almost entirely by people who made a conscious choice to not be somewhere else. So the majority of them are those who hold strong beliefs and are generally anti-establishment or just contrarian by nature.

Basically people most likely to argue about arbitrary bullshit a lot. Which isnt to say that all of them will, just that there 2ill be a higher incidence of it happening.

All propaganda has some element of truth to it, thats how they trick you into thinking its wholly believable.

Surface level honesty does not presuppose that same honesty at depth.

Hi, not the person you replied to, and (edit: not*) agreeing with any of this blocklist shit, AND my ire is firmly not shifted away from Tesseract, but just wanted to break down the characteristics of the OP that suggest (to me) it was composed mostly with an LLM and fine tuned after. (Though to be clear, that's a pretty unimportant characteristic of the post considering the actual content)

1. The division of the text into small "sections" of five or fewer short paragraphs separated by headers is probably the most obvious hallmark.

2. Kind of difficult to put into words, but abrupt / awkward / overly poetic metaphor and... "overconfident"? "sensationalized"? phrasing both give me an LLM vibe. examples:

It's a policy decision dressed as an API error, and it's what had db0 chasing a version mismatch that never existed.

I went through the code to see how that was implemented. The hardcoded list turns out to be the small half of the system.

The spam work is what makes the rest unauditable: "it's a spam list" answers every individual question and none of the whole.

It's downloaded at runtime from a file nobody has ever looked at.

spam filtering and political editorial got welded into one undocumented, remotely-updatable blob, shipped hidden

That's the licence working as designed. But forking isn't disclosure, and the admins who need this are precisely the ones with no reason to go looking.

1. Overuse of the rule of three. This one is probably the most tenuous, because genuine human writing does make frequent use of the rule of three. But when LLMs do it, it's usually at a high enough density where it starts sounding like it's trying too hard, or it's clickbaity.

Admins can't see it, can't configure it, and aren't told it's there.

That's the live policy, base64-wrapped gzip, 111KB of JSON when it unpacks.

There are Mastodon and Friendica accounts in there: people who have never used Lemmy, hidden by a Lemmy frontend, with no possible way of finding out.

355 of the 552 usernames are plain alphabetic, twelve characters or under, median length eight.

For the hidden users, communities and keywords, you get no message at all.

Self-host it and you cannot disable this, nothing in your config admits it exists, and the contents can change without you pulling a commit.

If you run Tesseract, you are relaying a 111KB moderation policy you have never read, under your instance's name, to users who don't know it exists.

1. Tonally inconsistent with the intended audience. I realize Lemmy/Fediverse users are more technically savvy than usual, but even then... consider the claim "I went through the code to see how that was implemented." early in the post. A lot of plausible technical jargon is used, and there are plenty examples of the actual filters and filter patterns themselves, but the post makes claims about what is happening without really being specific at all about how.

Could be explained by me just not being familiar enough with the technical side, but saying stuff like "There's a second filter policy fetched over HTTP every time the app loads" without breaking it down any further seems a bit suspicious to me? It doesn't actually call out any function, file, or... i dunno, a logical starting point, for a competent reader to dig into the source themselves. Reads like it's written for either an expert who doesn't need any details, or for an audience with zero skepticism whatsoever.

1. And least importantly, because my focus is on the presentation of the post moreso than the accuracy, IF rimu's read of the code is correctly calling out a factual error in the OP (and let me be clear that I'm not enough of a programmer to evaluate whether it is), that is pretty strong evidence of an LLM getting something wrong.

Again... this wall of text isn't meant as a refutation of anything you're saying, or a reason to dismiss the contents of the OP uncritically. Seems pretty clear after reading through db0's posts about it that this is seriously fucked up. I hope I've been clear enough about that.

dubvee has insane ban policies. Like they find people to ban based on posts in coms that have nothing to do with them. It’s almost like SRS on reddit.

Why is "^Yuri|^WholesomeYuri" in the community name filter? Why are anime lesbians hard blocked, while ani.social is just in the default user filter?

Filtered communities on instances that aren’t blocked: lemmy.ml/c/worldnews

ml is in the instance filter?

And this is why I run my own instance and use Summit....

you’re contrarian by nature.

Tons of political shit on that list and then midway through it just decides to ban yuri. Not porn, not furry content, and not hentai. Just yuri

Nuh-uh!

Touché.

censoring me

This looks almost like a personal block list that got added to the full production codebase. To be clear: I do not think this was an accident. But I had plenty of interaction with this dev on the 30 Rock community, and they were clear about personally wanting to use Lemmy as a means of escapism and to ignore politics of all sort. They clearly want to ignore all remotely political discussions, but that shouldn't extend to a hard-coded block list in a frontend they create for other people to use. Creating the tools to allow each user to set up custom block lists for themselves is great. It just shouldn't be a preestablished list that affects literally every user of that frontend.