Bat-Signal (The Dark Knight)

In the film The Dark Knight, James Gordon uses the Bat-Signal to remind Gotham of Batman's presence. The signal proves to be very effective, with drug dealers and criminals becoming apprehensive at its appearance. At the end of the film, after agreeing to blame Batman for the murders committed by Harvey Dent in order to preserve the former's image as Gotham's hero, Gordon destroys the signal in front of various members of the police force and the press.