why do I need no password to "unlock" my western digital 500 gb "my passpot" external drive. This is only on one of my computers. any other computer requires the password??? I plug in the external drive and the "unlock" menu pops up. If I just hit "unlock" with no password it unlocks the drive. I am concerned as I store a lot of other peoples personal health info on this drive and it must be encrypted at all times.