List owners:
 
I own two lists and edit a third. I have notices a growing number of
users cross posting message to various list.  If you look at a CC: you
see as many as 4 or 5 lists.  I personally end up get the same message
4 or 5 times.  E-mail etiquette states that cross posting is a no-no.
 
What does this list think about cross posting?
How does one handle cross posting?
 
I would like to send a message to my subscribers stating that they
should reframe for cross posting.
 
What should be said?
 
F. Leon