[Ianomed]

When staff use usernotes to comment on members, for instance to log notes for other staff members about spammers, it's not always an option to give the users access to their own usernotes.

Seeing as you wouldn't want to start a thread for each annoying member in your admin forums, usernotes are simply that: an admin tool.

When you still want to give users a way to keep track of half-finished posts, urls, etc. -> this hack comes into play.