messages sent to root logins

[Britton Bob]

I noticed that when a user tries to use sudo illegally, it not only reports
it to the syslog, but also displays a message to all users currently logged
in as root.  It can become annoying to others, especially when you're in the
middle of testing a change to /etc/sudoers to make sure it works right.  How
do I prevent sudo from displaying messages to root users currently logged
in, but still report them to the syslog?

Bob B.