What place does pure evil have in films?

In a time of dismay and dread, is it admirable for filmmakers to depict pure evil? Have 9/11, suicide bombers, serial killers and kidnappings created a world in which the response of the artist must be nihilistic and hopeless?

An introspective response by film critic Roger Ebert. He gets more space than usual to tackle this interesting topic, and to good result.