Hi, I just upgraded my 2012 Mac Mini to SSD. Everything works and is amazing, BUT: When I connected my old hard disk via USB I found that I had complete access to every last shred of data, no password, no nothing — FileVault notwithstanding. What's that all about? Is the disk only protected while it's built in? And doesn't that pretty much defy the purpose of my data being safe if the computer is stolen? What can I do to make sure that nobody can access my new hard disk? Thanks a lot!