So what happened to Facebook "localhost" tracking?

So what happened to Facebook "localhost" tracking?

106 pointsby juliusceasar102 comments

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  • Hacker News
  • i would love to have a software engineer's union, not so much to get better working conditions but to be able to say stuff like "i can't implement that unethical feature, it's against union rules and i'd lose my membership".
  • Take a lead, let me sign up :)
  • You don't need to join a union to push back against unethical feature requests.
  • I'd wonder how you'd get into that arrangement to begin with when the entire job is based on unethical tracking
  • Start one. Unions are worker owned. You could also join the IWW.
  • You could join the Order of the Engineer and refuse to do things that would not be compatible with your understanding of the Obligation of an Engineer [1]. Of course, that doesn't stop your employer from asking someone else to do it and asking you to find other employment.

    There's a few other orders or societies or what have you that you could join. Personally, I don't drive a train or even wear a stripey hat, so I haven't considered joining an organization for Engineers.

    [1] https://order-of-the-engineer.org/about-the-order/obligation...

  • Why not just ask for context and approval of the legal team? That would generate enough trail so some shady requirements get dropped almost immediately; having your superior explicitly sign off in writing a feature you deemed unethical and/or potentially illegal is a great way of actually removing them from the pipeline. You can even frame it as "a good guy" just alerting him/her that there may be a fallback, so make sure it has all necessary elements. Compliance decisions are often above a developers paygrade, and one should squarely document the culprit on any shady decision - and boy, this is very easy in big organizations where no single decision-maker wants to be accountable.
  • To be fair; you don't need a union... you can just say no. Context; I told them they couldn't ship this exact feature as designed. (It worked until I left.)
  • Off topic: I wonder how hard it is to poison this type of data gathering?
  • Is that a question?
  • Not hard, one could build an application that listens on common software ports and simply returns 200 for every request it gets.

    Not sure how it would benefit you telling some website you run all the software.

  • A timely question. Hopefully someone will share the recent Order and Third Amended Complaint

    Since that discussion in 2025

    Rose v Meta was consolidated with some other privacy cases against Meta

    A first amended complaint was filed,^1 Google was added as a defendant

    Defendants motion to dismiss was denied

    A third amended complaint was filed on Monday

    Here are the PDFs

    1.

    1st amended complaint

    https://dn711508.ca.archive.org/0/items/gov.uscourts.cand.45...

    Meta motion to dismiss

    https://dn711508.ca.archive.org/0/items/gov.uscourts.cand.45...

    Google motion to dismiss

    https://dn711508.ca.archive.org/0/items/gov.uscourts.cand.45...

    Plaintiffs response

    https://dn711508.ca.archive.org/0/items/gov.uscourts.cand.45...

    Meta reply

    https://dn711508.ca.archive.org/0/items/gov.uscourts.cand.45...

    Google reply

    https://dn711508.ca.archive.org/0/items/gov.uscourts.cand.45...

    Order

    (Payment required)

    https://pacer.login.uscourts.gov/csologin/login.jsf?pscCourt...

    2nd amended complaint

    (Payment required)

    https://pacer.login.uscourts.gov/csologin/login.jsf?pscCourt...

  • This actually inspired me recently to create Pal Pipe for Android- https://gitlab.com/not_john/palpipe
  • The May 11, 2026 Order on defendants' Motion to Dismiss has now been uploaded to the Internet Archive

    https://dn711508.ca.archive.org/0/items/gov.uscourts.cand.45...

    No claims were dismissed without leave to amend

    Defendants have failed to stop this litigation from going forward

    Expect a settlement before this moves into discovery

    The Court's understanding of "localhost" in this Order may be less than complete but if this litigation progresses further and experts are retained then that could change

  • I've recently been exploring options for allowing web apps to access LAN services. For example, a WebDAV server so you can watch local videos in the app without streaming them through a server.

    You can actually achieve a form of discovery if your service registers itself using mDNS for something like `service.local`. Browsers will allow direct navigation/redirection to `http://service.local`, but they'll block any fetch/XHR requests due to mixed content rules, even if you have CORS configured. And of course you can't get a cert for `.local` domains.

    Newer things like Chrome's LNA[0] are actually really helpful, because (for now at least) if the user grants the permission, fetch/XHR will go through, but you'll get a bunch of mixed content warnings in the console.

    It seems like the only way to fully support this use case currently is with WebRTC, which is pretty sad.

    [0]: https://developer.chrome.com/blog/local-network-access

  • Chrome and Firefox have deployed / are deploying local-network-access which prompts the user when apps try this.
  • Any idea if Safari is on board?
  • I've seen it and at least in Chrome it seems to be treating all URLs which are based on an IP address as "local", regardless of the class of the address.
  • I was just about to say that my question in regards to this was "what are web browsers doing about it?"
  • I just discovered that MacOS was blocking Firefox from connecting to devices on my LAN - there's per-app toggle in system settings.

    Access to my router's web interface was not blocked (understandably) but this left me rather confused for a while.

  • I guess that's why I am getting so many "Allow to find devices on your network" alerts. Good feature overall.
  • Looks like they stopped doing it

    https://localmess.github.io

    > UPDATE: As of June 3rd 7:45 CEST, Meta/Facebook Pixel script is no longer sending any packets or requests to localhost. The code responsible for sending the _fbp cookie has been almost completely removed. Yandex has also stopped the practice we describe below.

  • > almost
  • > Meta must face a lawsuit alleging that it secretly tracked Android users' browsing activity on mobile websites that embedded Meta's analytics pixel, and linked that activity to users' identities, a federal judge ruled Monday.

    > The decision, issued by U.S. District Court Judge Rita Lin in San Francisco, grew out of a class-action complaint initially brought last June by California resident Devin Rose (and later joined by other Android users).

    > Rose alleged that between September 2024 and June 2025, Meta exploited Android's localhost -- a feature that allows software developers to test applications -- to connect users’ mobile web browsing to their Facebook and Instagram profiles.

    May 12, 2026

  • im failing to see the connection

    >standard pixel tracking, linked to meta (js , web)

    >Meta exploited Android's localhost (os level)

  • > Judge RitaLin
  • Not at all to defend Meta but "a feature that allows software developers to test applications" is a dubious definition of localhost. I also can't come up with a better one.