On on hand, the sign is meant to deter potential thieves. The family starts to insulate themselves from the world because of their fear of it. They have built this large gate meant to protect themselves from the "threats" in the outside world and, in the process, the placard on the gates reminds the outsider of the warning issued. Yet, I think that the repetition of the placard and the manner in which the story develops might have the warning issued to the family. At each step, the family escalates their own fear and it seems as if each time, they are being warned that eventually, the real fear is not the outside world. Rather, the real fear that has to be confronted is their own sense of fear which is unrestrained. In this, the sign operates not to warn the outside world, but rather to warn the family that eventually what is happening will not and cannot have a happy ending or something fortuitous. In this, the ending of the short story is a brutal one, concluding with the ending of "You Have Been Warned" in terms of how the ending was almost a self- fulfilling prophecy.