rumor mill vs scandalmonger

rumor mill

noun
  • A process in which a group or network of persons originate or promulgate gossip and other unsubstantiated claims. 

scandalmonger

noun
  • A person who trades in gossip; one who collects and disseminates rumors. 

How often have the words rumor mill and scandalmonger occurred in a corpus of books? (source: Google Ngram Viewer )