How secure is NAS when you use user accounts and passwords for accessing to the folders but the NAS is not encrypted? (e.g. WD My Cloud DL2100) Can you read data from folders without knowing user name and the password? There is a folder called MyFolder and only Henry has access to that folder. Are files in that folder truly protected that no one can read it from internet or if the drive is stolen? What exactly user name and password do in NAS?