In Bradbury's Fahrenheit 451 why/how would a person be silenced for controversial beliefs?

Within Bradbury's dystopian society, the greatest crime is to read books that have substantial ideas in them. The people can look at picture books, but those do not give people complex ideas. The government wants to control people from having debatable ideas so everyone can live a free, distracted, and fun-filled life. Most people obey this law to the point that friends, neighbors, and even family can call the authorities on anyone who has books...

Within Bradbury's dystopian society, the greatest crime is to read books that have substantial ideas in them. The people can look at picture books, but those do not give people complex ideas. The government wants to control people from having debatable ideas so everyone can live a free, distracted, and fun-filled life. Most people obey this law to the point that friends, neighbors, and even family can call the authorities on anyone who has books and report them. Once an alarm has been sent out to the police and the firemen, the police show up first to arrest the person and the firemen burn the offender's home along with all of the books. The process is explained further as follows:

"The police went first and adhesive-taped the victim's mouth and bandaged him off into their glittering beetle cars, so when you arrived (firemen) you found an empty house. You weren't hurting anyone, you were hurting only things! And since things really couldn't be hurt, since things felt nothing, and things don't scream or whimper, . . . you were simply cleaning up. Janitorial work, essentially. . . Quick with the kerosene! Who's got a match!" (36-37).

Now, if the offender runs from the police rather than being arrested, the firemen have a Mechanical Hound that is given the person's biological and chemical scent. The technology of the hound cannot be surpassed. It can find anyone from any point in the city. Once it snags the person, the following happens:

". . . a four-inch hollow steel needle plunge[s] down from the proboscis of the Hound to inject massive jolts of morphine or procaine" (25).

Hence, offenders can either be arrested without incident as their home is being destroyed by fire (along with the books), or run and have the Mechanical Hound sent after them and suffer death by injection.