I don't think that squelching out other subscribers would be a good way to
reduce the noise on a list. It may be sometimes necessary on uncontrolled
conferencing (chat) systems but a LISTSERV list is different in many ways.
 
Though I think that a PLEASEBEQUIET <address> command would be extremely
helpful if you are struck by a mailer loop and can't do anything but curse
and delete that stuff. This is especially annoying when you see it start
on a friday night but are completely helpless until someone stops it the
next monday morning. (Sending mail to postmaster, root etc. @the mailer's
address usually doesn't help - for obvious reasons.)
Of course, such a command would be worthless for people who don't log
on frequently and at 'unusual' times.
 
If only one or two squelch entries per user would be allowed, it should
be neither a big performance problem nor should it be possible to abuse
this feature too much.
 
- Werner Almesberger