A year ago this week, everyone on Claude's Free, Pro and Max plans had to make one choice before they could keep using it.
Anthropic put it plainly: "We are also extending data retention to five years, if you allow us to use your data for model training."
One more line, from the privacy policy reads: rating a reply can store the entire conversation as feedback. Feedback is kept for five years.
So that irritated thumbs-down you pressed on some document summary may outlive the document.