The Clan of the Fiery Cross radio serial put Superman against the Ku Klux Klan, with accurate portrayals of their beliefs and rituals. Exposing their rituals and practices to public scrutiny was actually the whole point of that serial — due to a man named Stetson Kennedy who was attempting to undermine the Klan by exposing their secrets.
This was the entire purpose of Dragnet. Actual police jargon and correct procedures were used. Jack Webb was a stickler for detail, down to finding out how many steps it took to get to various offices at the LAPD headquarters. In one episode, he even recorded a scene at the actual location where the original story took place.