Probably a boring answer but I know my grandmother’s credit card information. I live with and help take care of her, so she doesn’t mind sharing it with me. Not like I’m planning to do anything nefarious, but I guess technically it could ruin her financially.
Lawyers, accountants, and software engineers accumulate these things like you wouldn’t believe. We can’t tell you about current secrets, only stale ones.
I once knew that the top level password used at a corporation valued at 6 billion dollars was ‘password123’. They had no backups, no VPN, and that password was used at all the high-value access points. It’s since been fixed, but it was that for years.