![Nestor Paiva](http://image.tmdb.org/t/p/w92/9QB3l3jN6npImyMvCHKWTMd7H8Y.jpg)
The "unseen guardians" of the title are the Postal Inspection Service, which investigates mail order racketeering; the Underwriters' Laboratories, which are shown testing electrical equipment, fire extinguishers, and large floor safes; and those who run orphanages, who assure that the children in their care are placed in proper adoptive homes.