As with other Bradbury stories, his message in this story is about the dangers of technology.
This world is one obsessed with television. Everyone is so devoted to it that no one even leaves their house anymore. No one goes for walks or socializes. This dystopian setting conveys the message that television controls every individual's life to the point of absurdity.
Bradbury also uses irony. It is ironic that a simple activity such as walking is enough to get a person arrested. This irony further develops the idea that technology dominates everyone's life -- and anyone who isn't obsessed with television must be breaking the law.
