oh i can assure you, the soviet union, china, NK etc are perfect examples of communism in practice. Hint hint, if the government can exploit the people with its absolute power, it will exploit the people.
Oh, you can, can you? Brother, Communism is defined as a State-less, class-less system where the people own the means of production. It's democracy in the purest form (not to be confused with western liberal "democracy"). This has obviously never existed. Communism remains a theory. Stalin, Lenin, Mao - they all said themselves that their systems were not Communist and is why they're known as Stalinism, Leninism and Maoism. They were more akin to State-Capitalism (which is still better than the west's Corpo-Capitalist system). They (Stalin, Lenin, Mao) controlled the corporations, rather than corporations ruling western governments today.