Madrid6 of 9 chatbot websites passed conversation data to trackers.
People tell chatbots about illness and money, and ChatGPT, Claude and Gemini were among those affected.
The IMDEA Networks study found chat titles, links, verbatim inputs and screenshots reaching third parties including Google, Meta and TikTok.
Android apps fared better, with 3 of 8 sharing conversation information.
Researcher Narseo Vallina-Rodriguez says the titles could be matched to profiles advertising firms already keep.
How each outlet framed it
- netzpolitik.org leans critical
- reports the tracking leak through chat titles and screenshots, not only message text; names Google, Meta and TikTok as recipients
Sources: netzpolitik.org