See It Now: "A Report on Senator Joseph R. McCarthy"

From Wikipedia:

See It Now focused on a number of controversial issues in the 1950s, but it is best remembered as the show that criticized the Red Scare and contributed to the political downfall of Senator Joseph McCarthy.

Murrow produced a number of episodes of the show that dealt with the Communist witch-hunt hysteria before embarking on a broadcast on March 9, 1954 that has been referred to as television's finest hour.

By using mostly recordings of McCarthy himself in action interrogating witnesses and making speeches, Murrow and Friendly displayed what they felt was the key danger to the democracy: not suspected Communists, but McCarthy's actions themselves. As Murrow said in his tailpiece:

No one familiar with the history of his country can deny that Congressional committees are useful. It is necessary to investigate before legislating. But the line between investigating and persecuting is a very fine one, and the junior senator from Wisconsin has stepped over it repeatedly.

The broadcast provoked tens of thousands of letters, telegrams and phone calls to CBS headquarters, running 15 to 1 in favor of Murrow. Friendly later recalled how truck drivers pulled up alongside Murrow and shouted, "Good show, Ed. Good show, Ed."

The show's probe of the McCarthy-led anti-Communist era is the focus of the 2005 film Good Night, and Good Luck.