The spam flood

I notice the spam flood has virtually disappeared from the other four
newsgroups I subscribe to.  It only seems to continue on rpd.

I know on one of my groups someone took action somehow to convert all
of those spam message titles to the word "spam", so it may be that
server administrators on host servers may have something to do with
overcoming the flood.  Don't know why it is continuing on rpd, but it
would be nice if this group somehow follows what is happening on rest
of Usenet.