Study: ChatGPT, Claude, Gemini leak chat artifacts to ad trackers
IMDEA Networks and UC3M found six of nine chatbot web apps (ChatGPT, Gemini, Claude, Grok, Perplexity, Mistral) send conversation titles, prompts, or screenshots to ad/analytics trackers—often with persistent IDs. Cookie rejection barely helps; Grok was worst, exposing public share URLs to seven trackers by default.