Technology is central to the lives of people in Bradbury's dystopian society, but its effect is negative in several ways.
First, technology is used to divert attention and to distract from more complex feelings and issues. We see this most clearly in the television programs broadcast directly onto the parlour walls. In doing this, the television becomes its own world, absorbing and all-encompassing, delivering a message which serves society, not the individual, as Faber comments,
But who has ever torn himself from the claw that encloses you when you drop a seed in a TV parlour? It grows you any shape it wishes. It is an environment as real as the world.
The Seashell radio, used daily by Mildred, is another example of this invasive effect of technology. Mildred has used hers so much that she is now an "expert in lip-reading:" the Seashell has cut her off from everyday interactions with others.
If technological entertainment is used for distraction then the Mechanical Hound, another form of technology in the novel, is used to silence and oppress. Though a robot, this fierce Hound is able to sniff out instances of crime:
It would be easy for someone to set up a partial combination on the Hound's ‘memory,’ a touch of amino acids, perhaps. That would account for what the animal did just now. Reacted toward me.
In Part Three, the Hound's true capabilities are demonstrated when it kills a man it believes is Montag but is in fact a complete stranger who has not committed a crime.
This destructive aspect of technology is also illustrated through the constant references to military helicopters and the atomic bomb; both are used for the purposes of total annihilation. In fact, the novel closes with the complete destruction of the city, a potent symbol of technology's dark side.