when downloading newsgroup headers from news servers which haven't yet   
universally (*) purged retained articles containing "
googlegroups.com"      
in their path/message-id headers, 
googlegroups.com articles may appear           
in the downloaded header list unless your newsreader client is already    
set to filter them out (reference headers may include 
googlegroups.com     
so be sure to filter those as well); also, when responding to articles   
in threads which may contain 
googlegroups.com in the reference headers,           
simply delete the 
googlegroups.com article reference from such replies  
and snip all or most of the quoted text attributed to 
googlegroups.com