I stopped installing at the request for "your data on all websites". I didn't see anything in the privacy policy that explains why and how far "my data" travels

I stopped installing at the request for "your data on all websites". I didn't see anything in the privacy policy that explains why and how far "my data" travels. Could you explain that a bit more? Otherwise I'd love to try it out - I periodically bemoan the suckiness of bookmarks.