Reddit is blocking users based on user agents?

ISOmorph@feddit.de to Reddit@lemmy.world – 626 points –

Started to get this message when accessing Reddit. I use LibreWolf as a browser, which does indeed provide a more generic user agent to combat fingerprinting, but nothing out of the ordinary either (Mozilla/5.0 (Windows NT 10.0; rv:109.0) Gecko/20100101 Firefox/119.0). Anyone else experiencing this?

Edit: seems to have resolved itself. Thanks for confirming I wasn't doing anything wrong. Let's hope this isn't some new algorithm to test if for insufficient fingerprinting so Reddit can kick ad-resistant users.

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It also tells the website the OS you're running, as well as the browser, and various version numbers of stuff.

One interesting experiment is to use a user agent changer to view a website, and watch how the website changes every time you load a new user agent.

Google will remove search options if you're using Firefox (mobile?), for example. But if you change your user agent to say you have Chrome, even if you are actually using Firefox, those options magically come back and work. It's almost as if that's anti-competitive behavior or something...

It's also how a lot of websites know whether or not to give you Windows executables or Mac executables, or Linux executables, etc.

Firefox with user agent as chrome

Firefox with user agent as firefox

Holy smokes, the whole graph is removed.. and they moved up "Shopping"

Brilliant example. I think some of the search tools like date range or image color also get removed with the Firefox user agent, but I don't quite remember.

It also tells the website the OS you're running, as well as the browser, and various version numbers of stuff

While it's true that many browsers choose to follow a convention that includes that info, User-Agent is just a string, so something like fuku is a legitimate UA

https://www.rfc-editor.org/rfc/rfc1945#section-10.15

curl -vA fuku example.com 2>&1 | grep -E '^[<>] (User|HTTP)'

Before the paranoid think it's invasive, it's used mainly to tell the website what your browsers capabilities are, so that features work and render properly. And by "tell the website", I mean they generally serve the same "code" to everyone, and your browser just uses different parts of it.

It's not as big of a deal now, but browsers used to render things very differently and had unique style features. Safari is still a big offender of this.

The above Google search features probably means the developers being Google, probably just thoroughly tested the more niche features on Chrome. And probably at some point, other browsers like Safari shit the bed (common) because they used features that Safari didn't support at the time, and decided to just disable them for Safari.

It's also used to create a digital fingerprint so you can be tracked without downloading a cookie.

Uhh, I'm unaware of how that's even possible. There is no uniquely identifiable information in the UA. Everyone keeping their browser and os up to date are going to fall into the same few buckets. Are you pulling that out of your ass, or do you actually know of a technique that abuses it?

It is one of dozens of things used to establish a unique fingerprint. Check this out, I bet you can be individually identified and tracked with nothing more than what your browser reveals, including the UA.

https://amiunique.org/

Reddit uses exactly this to enforce site bans so they can identify people that just change emails or even public ip addresses. It's almost certainly used to create phantom profiles at hundreds of sites whether you make an account or not.

https://smartframe.io/blog/browser-fingerprinting-everything-you-need-to-know/

Not the person you're replying to, but I would second what they're saying. I recall many years ago reading a post from the Tor browser team explaining that they customise the UA and even browser window size to avoid fingerprinting. It's not the UA alone, but that in combination with other values the site you're visiting can detect.

User agent is also the very first thing checked on the below fingerprinting site. I was surprised to see that 0.00% of me have the same user agent as me!

https://www.amiunique.org/fingerprint

I think that they probably made it so their app looks nicer and want chrome to match, anyway then there's apps that just block you if you're not using chromium or derivatives, despite working on the browser you're using. Ahem Ms-teams and another video conferencing software that I had to use.

Yeah I didn't think disabling features for Firefox users would make sense. The user would have to know you're punishing them for it to be effective at incentivising them to switch to chrome.

I personally don't trust Google anyway and mainly just use duckduckgo.

Google also changes a bunch of features if you change the user agent to some really old or non existent browser versions.

I don't think they are making Firefox worse on purpose. I think it's just something they don't bother to fix.