Private note creation
The note tool is intended to package the note in the browser before a share link is produced. In this static build, the encrypted package is placed in the URL fragment.
Analytics and logs
Site operators may still receive ordinary hosting, analytics, and diagnostics information about page visits. That is different from intentionally storing the plain-text content of the note itself.
Contact messages
If you email the site directly, that email is handled like a normal message. Do not use the contact address to send the content of a private note.