Several movies nominated for Academy Awards – "Letters from Iwo Jima," "The Departed," "Pan's Labyrinth," "Apocalypto," and "Babel" – have levels of realistic violence that were unfamiliar on the big screen a generation ago. Network television, too, has kept apace with the big screen's inflation of gore: witness the brutality in an average episode of "24," "Prison Break," or "Heroes." Meanwhile, video-game manufacturers are finding ever more creative ways for players to kill off virtual foes on computer screens.

Depictions of violence have always been a popular element in storytelling, but each of us can recall instances when we've been caught unawares by the graphic nature of violence in a piece popular entertainment.

Before seeing a movie or TV program or buying a video game, how do you learn how much violence to expect? Do you feel that the resources available to you are adequate?