I’ve come across two techniques for disabling the Message-of-the-Day, or MOTD.
The first is described in Essential System Administration by Aeleen Frisch.  It involves two files. /etc/login.defs and ~/.hushlogin.
/etc/login.defs contains the default settings for login, account creation and modification.  The setting we’re interested in is HUSHLOGIN_FILE.  The HUSHLOGIN_FILE setting controls the name of the file that controls whether a user sees the MOTD or not.   Setting HUSHLOGIN_FILE to .hushlogin means, if there is a file in the user’s home directory named .hushlogin, the MOTD will not be displayed at login.
The second technique is described in the login(1) manpage.  It states, creating ~/.hushlogin will quieten the login process, but it does not mention having to edit /etc/login.defs.