Highly doubt it's millions. You have to upload a non-native format into Drive, modify the default security settings, and be linking to another HTTPS site and so

Highly doubt it's millions. You have to upload a non-native format into Drive, modify the default security settings, and be linking to another HTTPS site and someone has to follow that link. AND the information in the original document has to be sensitive. The odds of that are very, very low.