Entire conversations via exposed permalinks. For Grok: trackers receiving the conversation URL could access the full chat because the link lacked access controls.

Screenshots of conversations. TikTok received screenshots of Grok chats during sharing, exposing the actual visible conversation content.

Conversation-derived content tied to persistent identifiers, including prompts and automatically generated chat titles revealing sensitive facts. "Salary 85k NYC: mortgage 280–350k".

"multiple providers disclose sensitive conversation-derived artifacts — including titles, prompts, and screenshots — to third parties, often alongside persistent user identifiers that enable user attribution. We also find that some providers publicly expose conversation permalinks without access controls, allowing trackers to read the entire conversation."

Not good at all.

Is it still called a leak if it was the whole point and purpose of the deal?

Someone should have to investigate, but I suppose it's all "legal"?

The paper doesn't say when the app sends the conversion artifact.

The word is "sell" not "leak". This title takes away all agency from the thieves selling private data to advertisers.

All sells but I saw Chinese models are upfront about that most of the time.

my first guess is always Gboard.

This is a bit surprising to me, considering how much AI companies love to hoard data. Especially since some of these ad companies are direct competitors!

My best guess is that these ad mechanisms are a bit rushed and/or that investor demands for profitability are fighting against company self-interest.

Edit: I guess some data will always need to be leaked for AI chat ads to be most effective. But I imagine AI companies would rather deliver the targeted ads themselves rather than letting competitors do it for them. It would be scary to see AI companies become ad companies too (instead of just hosting them).

You thought... they didn't?