One may believe, as I do, that communism would destroy all of our freedoms, one may be opposed to it as firmly and as strongly as possible, and yet, at the same time, also believe that in a free society it is intolerable for a man to be prevented from making voluntary arrangements with others that are mutually attractive because he believes in or is trying to promote communism. His freedom includes his freedom to promote communism. Freedom also, of course, includes the freedom of others not to deal with him under those circumstances. The Hollywood blacklist was an un free act that destroys freedom because it was a collusive arrangement that used coercive means to prevent voluntary exchanges.
Read more excerpts from "Capitalism and Freedom" by Milton Friedman!