As the title says, say you wanted to go to a public library and read a copy of Das Capital or the Communist Manifesto, how hard/easy would it be to do so during the second Red Scare, or the Cold War as a whole?

I don't imagine it would be easy for the government to out and out ban an author's works when it played such a large role in history, but were there any extra requirements when reading Marx's works? Did you have to, say, explain your reasoning for reading them? Would you be put on any watch lists?