OpenAI’s ad cookie ties ChatGPT accounts to advertiser websites.

OpenAI can connect what users do on those sites to their ChatGPT account, the researcher found.

The browser attaches the __obi cookie when loading an advertiser’s OpenAI script, before any OpenAI code runs.

The signed token expires in 60 seconds, but the cookie it sets lasts a year.

The researcher logged 936 advertiser pixels across 1,029 hostnames over several months.

How each outlet framed it
Hacker News leans critical
reverse-engineers __obi cookie mechanism with JWT auth; verifies tracking across 936 advertiser pixels on 1,029 hostnames

Sources: Hacker News