In November 2007, it was revealed "that firefighters are being trained to not only keep an eye out for illegal materials in the course of their duties, but even to report back any expression of discontent with the government.”
“A year ago, Homeland Security gave security clearances to nine New York City fire chiefs and began sharing intelligence with them. Even before that, fire department personnel were being taught ‘to identify material or behaviour that may indicate terrorist activities’ and were also ‘told to be alert for a person who is hostile, uncooperative or expressing hate or discontent with the United States.’”
Fahrenheit 451 is not a work of fiction anymore.