dragnet vs trawling

dragnet

noun
  • A net dragged across the bottom of a body of water. 

  • Heightened efforts by law-enforcement personnel to capture suspects. 

verb
  • To make heightened efforts to catch a suspect. 

  • To drag a net across the bottom of a body of water. 

trawling

noun
  • A commercial fishing technique in which a net is dragged by a moving boat. Not to be confused with trolling, which drags (one or more) lines. 

  • A laborious search. 

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