One of the most annoying features of Windows Vista is the login screen that displays all user accounts on the system. You have to click on one of the accounts and enter the password from that user to be able to login and use Windows Vista.
I don’t think it makes that much sense to display this information if you login with the same user most of the time. Security should also be no concern because it is not that complicated to access the data even though you do not know the password of that specific user.