The giant is discovered due to his unceasing appetite for all things metal. When he makes the mistake of trying to devour an electrical power station, a small boy rescues him by turning off the power switch and becomes his friend. The Iron Giant has the mind of a small child and has a large appetite to learn. The boy teaches him that he can emulate Superman rather than another comic book character, which is an atomic monster. He has the power within him to be either.
Technology is a lot like that.
Its power can be harnessed for good or evil and history shows us that it has. As the Internet, lower cost, more powerful computers, and wireless communication become more within the reach of every adult and child, parents, teachers and other adults have an onerous responsibility. A child's voice in the theatre that day said it best. In the movie, the boy asked the Iron Giant to stay in the forest and wait for him until the next day. The Iron Giant followed him instead.