> I have been on one or two other lists which were destroyed by a troll
> such as cr, but the moderators of those lists, who had not the wit to
> prevent the damage, at least had the dignity to shut the lists down.
TSE is an unmoderated list. Anyone can join or quit at any time.
My own feeling about the lists I belong to is that anyone can knock on the door, but there's no need to answer it. A click clears out one's In Box.
If the (silent) knocking of a troll seems bothersome, however, simply set up a filter (very easy in most mail programs) to send the troll's messages straight to the Trash.