I wanted to sketch a database schema last month and the first three whiteboards I opened asked me to sign in. So I wrote my own. While I was at it I decided the no-upload thing shouldn't be a line in a privacy policy, because you can't check a privacy policy.
Source: [Dev.to](https://dev.to/pop3_zxcv/a-whiteboard-that-cant-upload-your-drawing-because-the-browser-wont-let-it-302f)