Verify That There Are No Accounts With Empty Password Fields

An Account with an empty password field means that anybody may log in as that user without
providing a password at all. All accounts should have strong passwords or should be locked by using
a password string like "!!", passwd will warn when attpting to unlock an account with an empty password.

The Command:

awk -F: '($2 =="") (print $1)' /etc/shadow