Today's discovery is that a Netgear ReadyNAS Duo, when creating a new user account, "helpfully" emails the new user with their password. This is... undesirable, when the new user account has the same name and password as the one I use on my local computer (because single-sign-on makes everything much nicer to use). This is especially undesirable when the reason my local account is passworded is so that I can safely enable remote access for it.
I suppose it did at least send the email using TLS.
Fortunately it doesn't email when changing passwords. Lesson learnt: create account with dummy password, then set it to super-secret-squirrel password.