I did a little research and quickly came up with a simple process that was shocking! Simply:
- Starting the Mac with two keys pressed brought it up in a terminal session logged in as root (the most authoritative user on the system).
- Three simple commands produced a list of all users on the computer (their short names), and
- One more command allowed me to change any of those users' passwords to whatever I wanted.
- Then a simple reboot allowed me to login as them with their new password, giving me access to all of their files!
Are you kidding me, Apple?!!? Can't you at least require a password or some other methodology to protect the files on your computers?