In "Fahrenheit 451" what does the quote: "Twenty million Montags running, soon, if the cameras caught him" mean?
This quote is actually quite a horrifying one, if you grasp its meaning well. At the end of the novel, Montag is on the run from the law and from the mechanical hound, who has already stabbed him in the leg. He has just murdered Beatty, and openly rebelled against the law. So, he takes to the streets, and tries to run away and hide. As he is running around, he notes that every house is lit up with the glow of their television sets and walls. We can relate to this--if we are driving down the street at night, we can see the blue-ish glow of t.v. screens through windows of houses that we pass. Montag realizes that virtually everyone in his entire city is at home right now, sitting in front of the television. If somehow a helicopter were to spotlight him and find him running through the streets, they would for sure broadcast the chase on the televisions, and millions of viewers would instantly know that he was on the run.
Think of the high-speed car chases that interrupt programming sometimes; this would be the same thing, except for a chase of a lone man, Montag. He remembers one time that they recorded a man who just liked to go out for walks; a broadcast interrupted their shows, and everyone in the city got to watch as the hound and government hunted this man down and got rid of him. If everyone can see Montag on their t.v., they will all know that he is a fugitive, and if any of them recognize where he is, they can call him in or help to get him caught.
Montag, aware of this potential danger of being broadcast, tries to stay hidden, and away from anyone who might see him. I hope that those thoughts helped a bit; good luck!