unsafe file permissions on /usr/bin/login

The suid bit is set on the /usr/bin/login binary.  This results in the
system being susceptible to a manual (login) attack on user accounts
(including root).  An attack can be initiated by any user with a shell.
(Also, consider a system with no root password - my preferred)

I briefly looked through /usr/src (grepped for '/usr/bin/login') and the
only use I found of it was for the csh `login` built-in.

My suggested fix (untested): the csh `login` built-in should be restricted
to the superuser and the /usr/bin/login should be mode 555.

Any thoughts?

Is login used anywhere else in the system (and by an unprivileged user)?

JP