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ChatGPT now knows what you do on other websites via ad collector
OpenAI’s ChatGPT sets a cross‑site cookie (__obi) that advertisers’ ad‑pixel scripts automatically send back to OpenAI, linking browsing activity on third‑party sites to a user’s ChatGPT account. The author reverse‑engineered the token exchange, captured traffic from hundreds of pixels, and quantified the data collected (emails, phone numbers, locations, page paths). The mechanism works for logge…