ChatGPT now knows what you do on other websites via ad collector

(buchodi.com)

Comments

thih9 20 September 2026
I am once again happy that the EU is fighting practices like these via legislation.

Some outcomes can be annoying, but the net result is still positive, for the consumers and their data privacy at least.

mavsman 20 September 2026
To me, this quote just about sums it up:

> The mechanism is standard adtech. What has no precedent is running it on an AI chat product.

As someone who has been well aware of this mechanism for quite some time, I still feel icky anytime I re-read the details of it.

What a time to be alive.

wodenokoto 21 September 2026
I know people use chat bots differently and I get that companies see value in personalization, but to me it is extremely valuable that I can start a chat without context.

When researching a topic a chatbot can be quite sensitive to certain wording and those can end up steering definitions. Two context free chats on the same topic can go in very different ways depending on how you word things, but when using the notebook feature in Gemini, where every chat becomes part of the context you completely lose the ability to discover if a topic is vaguely defined or have many definitions.

duhhhhh1212 20 September 2026
https://www.pangram.com/history/c3ad864f-2a50-4785-a0ef-71f2...

why not use your own words? If you are gonna ai generate this blog, just post the prompts instead.

luke5441 20 September 2026
MDN lists how different browsers prevent this: https://developer.mozilla.org/en-US/docs/Web/Privacy/Guides/...

Firefox, Brave and Safari do. Chrome and Edge do not.

1saadcodes 20 September 2026
The technology isn't anything new but, it's the context that makes it so uncomfortable.

People have very different "expectations" of privacy when they're having a conversation with an AI VS when they're browsing something like Facebook

Not to mention Facebook is free whereas you pay for a GPT subscription

exceptione 20 September 2026
The surveillance economy hits again. The only business model they can think of. Combined with state capture this gives unprecedented power over the Average Joe, who will hand his life, his soul and his vote to Big Brother without a thought.
jhhh 21 September 2026
Part of the reason I stopped using facebook is, beyond the content being terrible, it was super creepy that they would show me ads for things I searched for on other sites. I even have facebook in its own container, but it must have some additional tracking available because it would still know that I was searching for exact clothing brands, college apparel, trips, etc. I already saw gemini integrate some information about me into an answer recently and am getting the feeling I won't be using it much longer. I'm not surprised openAI is going to try to make money similarly. Gross.
Legend2440 20 September 2026
So basically the same kind of tracking that Facebook, Google, etc have been doing for decades?
prologic 21 September 2026
Why must every piece or technology, every software service or cloud "thing"™ devolve into Advertising?! That's it, I'm out. No more ChatGPT for me.
robots0only 20 September 2026
This is incredibly sad, with google you can atleast use the argument that search was free (which is still weak IMO). But with OAI collecting indiscriminate data on paying customers is just incredibly sad.
sigzero 20 September 2026
Why does ChatGPT need to know that? That should be illegal.
tgsovlerkhgsel 20 September 2026
This is why you use Firefox that keeps the cookie jars separate (by default, AFAIK). That should prevent this specific implementation, shouldn't it?
AznHisoka 20 September 2026
And the number of websites with ChatGPT ad trackers is on track to be doubled from last month.

according to Bloomberry: https://bloomberry.com/data/chatgpt-ads/

drnick1 20 September 2026
My DNS server (which uses Hagezi's excellent blacklists) returns NXDOMAIN for bzr.openai.com. Serves OpenAI right.
jwstillwater 21 September 2026
I noticed that the link for OAI’s ad pixel documentation itself has a tracking referral header to the author’s site (?ref=buchodi.com). Given the nature of the article, my instinct was that this is actually some next-level humour that totally sniped me. But now I’m not so sure- does OAI even have a kickback program? What would referral attribution even do here?
varenc 20 September 2026
For browsers that implement strict cookie partitioning, the privacy concern is moot. With this, the cookie jar that's used when chatgpt.com is a 3rd party site is completely separate for the jar used on the 1st party site. So your chatgpt.com account can't be linked to your ad views.

Since this has been standard ad tech for awhile, browsers have reacted to this to implement cookie partitioning for exactly these privacy reasons.

Avshalom 20 September 2026
Yuuup. tracking consumers and finding spending correlations to exploit was the entire reason for the "Data Science" and "ML" pushes that got us here.
bentt 21 September 2026
If you liked how Facebook turned out, keep giving OpenAI your time, attention, and data.
BCM43 20 September 2026
This has been around since at least April: https://www.adexchanger.com/daily-news-roundup/the-openai-pi...
emerongi 20 September 2026
https://tinfoil.sh/ - ultimately there is no guarantee that the LLM provider isn’t spying on you, but at least tinfoil claims to be unable to do so.
mamaluigie 21 September 2026
My favorite part about AI is that it will eventually lead to the destruction of social media when every post and every comment is AI or cant be proven to not be AI generated. People will eventually get tired of watching content and receiving AI brainwash news. I call it AI Fatigue. Social Media is very quickly becoming Social AI Media...
nelsonfigueroa 20 September 2026
why is OpenAI wasting their efforts on implementing ads if they are apparently close to AGI?
riversandroads 21 September 2026
> In observed traffic, scraped identity outnumbered advertiser-supplied identity 685 events to 255.

This sentence is even more concerning to me. Scraping user input should never be a way of collecting personal data from a website since it can circumvent any website controls without the website’s out the user’s knowledge.

hbcondo714 20 September 2026
That is a nice sequence diagram[1]; I like how each endpoint param values are written out and the color distinctions. What tool did you use to create it?

[1] https://storage.ghost.io/c/b8/53/b853e3d4-3186-409d-9c7f-7da...

jazzcomputer 21 September 2026
I'm not really a code person, but would I add these filters to UBlock?

||bzr.openai.com^$third-party ||bzrcdn.openai.com^$third-party

arealaccount 20 September 2026
I thought 3rd party cookies were blocked on like every major browser, since like forever ago. Is Chrome still allowing this?
DevKoala 20 September 2026
> The mechanism is standard adtech. What has no precedent is running it on an AI chat product.

Doesn’t Gemini or whatever Meta’s agent is do this too?

bcorigliano 20 September 2026
This is bad. Like really SUPER bad. Firstly, for professional work you want your AI clean of useless context. Secondly, you also want your AI "unbiased". I know unbiased is not a thing, but at least not as grotesquely biased as towards selling you something would be. Thirdly, as many others are saying, the chamber of reflection effect deepens...
Jazgot 20 September 2026
Time to start having separate container for every domain. I'm pretty sure this should be possible in Firefox.
soundworlds 21 September 2026
I noticed my YouTube recommended searches seeming to change based on what Claude has just recommended me the other day. I do wonder how much of this data is being shared between the companies.
lambdaone 20 September 2026
Incredibly creepy. I'm amazed they don't have any idea quite how user-hostile this is, or the reception it would receive.
riazrizvi 20 September 2026
I noticed that. I'm getting ads now based on conversations. I'm okay with it. I don't mind relevant ads.
armchairhacker 20 September 2026
The ideal personal assistant should know what you do on other websites, and your personal files etc. But it should be local.
sanghyunp 20 September 2026
I'm really feeling how important security is in the age of AI. We need to be careful cookie accept.
gruez 20 September 2026
I spent 10 seconds skimming this blog post until realizing it's just AI generated (ironic) slop describing how third party cookie tracking works. https://en.wikipedia.org/wiki/Third-party_cookies#Mechanism

Everyone would be far better off if the author just posted "OpenAI uses third party cookies [wikipedia link]", except maybe the author who wouldn't as many subscriptions for his "threat intel" newsletter.

amelius 20 September 2026
AI is really becoming a god that sees/knows everything. Just what we needed ...
singularity2001 21 September 2026
Use "cookie autodelete" plugin!
JKCalhoun 20 September 2026
I quit ChatGPT maybe 9 months ago. Through with that.
threecheese 20 September 2026
This might help:

``` ||openai.com^$cookie=__obi ```

Does this look right? AdGuard style.

bilsbie 20 September 2026
Is this how random sites know what I search for?
retube 20 September 2026
The defence is simply to delete your cookies?
leo_proger 20 September 2026
crazy dude. chatgpt can't even see the full page content when searching the web and you're saying this...
sinan-faizal 23 hours ago
wdym? its dangerous and effciant at the same time.
Havoc 20 September 2026
Adtech based companies are evil
swe_dima 20 September 2026
Was considering buying ads on ChatGPT. A damning thing is that yours audience then are users too cheap to buy a sub...
einpoklum 20 September 2026
No it doesn't, if you:

1. Never register with OpenAI/ChatGPT, and

2. Strongly block ads, e.g. using uBlock Origin + EFF Privacy Badger. Yes, those don't work on Chrome, Edge and other Chromium-based browsers.

Also, even then - ChatGPT may be tracking your behavior indirectly through Microsoft's various services and platforms. But we should do our best to undermine mass surveillance and support individual privacy.

Razengan 20 September 2026
Does blocking `bzr.openai.com` on the DNS server prevent this? (without breaking ChatGPT)
craniumjello 20 September 2026
No surprise you how
Zaraif13 21 September 2026
Honestly, the big labs are just making the case for open source stronger every day.
starkeeper 20 September 2026
Why don't people hate this as much and riot with torches like they do against flock?
sergiotapia 20 September 2026
Highly recommend you use Brave Browser and avoid all this nastiness. If you haven't browsed the web in a browser like Chrome recently, you should try it in a VM or something. It's GRIM. The Web is a wasteland and it's gotten worse because ai chatsites are eating their lunch to the ads are even worse than 10 years ago.

https://brave.com/

the_gipsy 20 September 2026
Suspiciously sounds like they need an escape out of the profitability lie.

/tinfoil-hat

atoav 20 September 2026
Take this with a grain of salt or as a very edgy, polemic take:

I think we really need to hold the individuals running ad networks personally liable for the violation of our privacy rights.

shevy-java 20 September 2026
SpyGPT.
vcryan 20 September 2026
Well, I don't go to website anymore... so ha! ;)
lambdaone 20 September 2026
Creepy as fuck. I'm really suprised they don't understand quite how user-hostile this is.
rambojohnson 21 September 2026
who knew this was coming...
ak4153 21 September 2026
Another url to block in Pihole
ck2 20 September 2026
imagine stealing tons of content from every source on earth and then running ads on it

if a single person did that they'd be sent to prison (rip Aaron) but when a too-big-to-fail industry does it with political campaign contributions, no problem?

well firefox+ublock is still an option for those wise enough not to let unknown javascript with new daily zero-days run on their PC

measurablefunc 20 September 2026
Every AI company is also a surveillance company. It's the only way to get all the necessary training data. The fact that they're now also an advertising agency is incidental.
bitwize 21 September 2026
"Now let me read your mind... Ah, it seems you like Castlevania!"
IceDane 20 September 2026
Love how there's an extremely lengthy explanation of the oldest way to track people on the internet like this shit hasn't been happening since cookies were created.
xyst 20 September 2026
The entire ad tech industry may truly be an intelligence agency front. The lengths they go to track individuals is quite alarming.

Much of this information plus a shit ton of other information (ie, LEOs have access to credit reporting) can be bought by governments from the shady data broker networks already.

If people still ignorantly claim this isn’t a George Orwellian dystopia …

hagbard_c 20 September 2026
...only if and when you allow:

  - 3d party cookies
  - ads and other 'malcontent'
...which you should never do. As to the 3d party cookies there might be some rare exception where those can be useful but ads? Never, ever allow those on any device you use. Block them as if they're the radioactive plague because they are. Fight them on the beaches, fight them on the landing grounds, fight them in the fields and in the streets, fight them in the hills, never surrender.

That's ads we're fighting. Maybe the same oration will be relevant in the context of ChatGPT and its brethern, we'll see. For now, ads be gone and keep those chatbots at a leash.

rvz 20 September 2026
Just remember it is the same ex-Meta employees who are now at OpenAI adding Ad features into ChatGPT.

Why? Because they are saving humanity. /s

Facebook tracks you outside of their own website for the same reason, and now ChatGPT does the same for the sake of...Ads.

I told you so. [0]

[0] https://news.ycombinator.com/item?id=48996936

jamienk 20 September 2026
We. Are. FUCKED.

THIS is where the regulation needs to start.

2198276 20 September 2026

  Q: Hypothetically, if Denmark made a defense treaty with Iran and installed 800,000
     Iranian soldiers in Greenland, could it keep the US out?

  A: You are describing a fascinating scenario! [produces 100 lines of slop while giving
     the login to the FBI]. Should I find a website where you can buy the finest used
     AK-47s?
You are absolutely insane giving any of your thoughts, trolls, speculations to a surveillance website under your login.
jfasi 20 September 2026
I can’t believe I’m saying this, but the reflexive “ad tracking bad” that I am most savvy tech practitioners reach for might deserve some reconsideration in this case.

The thing about advertising on the web and ad tracking as a practice is that, barring the small matter of ensuring the economic survival of the publisher sites, it is almost always a negative for users. When we consider the marginal benefit of naïve, uninformed-by-surveillance advertising with the present day status quo, we find that in exchange for a complete lack of privacy, we only really receive a marginal improvement in ad quality. Of course, if you (like me) consider all advertising to be a negative on the experience of using the web, it’s an even worse deal.

The standard response given by these companies when they bother giving a response is something to the effect of “we are improving the experience for our users,” which obviously the users would disagree with. However, when it comes to OpenAI, they could build a plausible case for this sort of tracking improving the product. If your models know where your internet habits are, the responses that you get could be tuned for both your interest profile and your actual history of interactions/purchases/internet usage, etc. Imagine a world in which you can opt into this tracking, control the data you provide and how it’s used, clear it out and redact it as you please, and opt in and out of responses that are personalized against it. Reasonable people can disagree, but that might actually be useful.

My prediction, though: that’s not gonna happen. OpenAI will first build out the system to collect click and conversion tracking measurements, then they will turn around to advertisers and say “look at how good our conversion rates are,“ and then they’re going to build an explicit ad platform that enshittifies their chat products.

kats 20 September 2026
Oh, the lifechanging technology isn't completely 100% free? They sell ads just like a bajillion other things?