Using the 4 digit PIN on the Norton Safe mobile app is very convenient.
But, since it doesn't logoff from Norton Web when someone else tries to guess the PIN it's not as secure as it could be.
Background: 5 incorrect PIN tries does logoff the vault but the password to the vault is much shorter (less secure) than that of Norton Web... so I'd prefer it logoff Norton Web, too, when someone else tries to guess the PIN.