Invalidating Users (temporarily)

[James Nau]

Does anyone know of a way to invalidate a user so that a message is
displayed, and the user is logged off, and ftp access is disabled?
I've tried replacing the shell with a program that prints out a
message.  Worked great.  But that still allowed FTP access to the account.

The only alternative that I can see is to either a) change the password
on the account, or b) mark that password in /etc/passwd to be a "*".
Both of these will disable the account, but won't allow a message to be
printed.

Also, I'm running NIS, but that hasn't mattered (that I know of) for
what I've tried.

Thanks
James

james at engrs.unl.edu