These are home-grown scripts which are used as users' shells for various purposes
This is the shell a user initially gets when they first activate their account. They keep this shell until they accept the AUP, so that by definition anyone with a proper shell on a netsoc machine has accepted the AUP.
If the user accepts the AUP, they are prompted to bind to LDAP (via nd), and their shell is set to the default shell (currently set in LDAP as /bin/bash).
These older scripts used to be used on spoon and matrix to prevent bold, expired non-renewed and dead accounts from logging in. These days they've been replaced by groups in LDAP, and a Match Group clause in /etc/sshd_config.