1) Why Group password is hardly used in Unix?
2) In /etc/group all my groups do not have password i.e
<groupname>: :<users> -> the password's field is blank, in this case I believe that the password is not set, but why if users would like to change group i.e newgrp <group> they asked for a password? I checked on /etc/gshadow the following group does not have encrypted password in the file.
3) Suppose that I add a new group by runnning command like
groupadd <newgroup>, How to add a new group without having set a new password for them?