You have modified user bob’s login information. In the passwd file, you changed /bin/bash to /bin/false. What effect will this have on user bob?

A.
Bob’s account will run the false utility

B.
This will not effect Bob’s account

C.
This will change the user’s UID

D.
This will suspend Bob’s interactive login

Explanation/Reference:
This has the effect of rejecting shell login attempts over ssh, telnet, or other shell-requesting protocols. It may have other side effects too, but those are beyond the scope of this article.

CAUTION: Simply using /bin/false as someone’s shell does not keep them from using said account to authenticate over ssh and using non-shell tools such as port forwarding. A default configuration in sshd will often allow tunneling and other non-shell activity.