[snowwrestler]

I think it's important to be clear about what you mean by the word "censorship."

Generally it's considered to be a restriction on freedom of expression by a system of legal authority. Generally it is not thought to include matters of private choice and contracts, even if the sanctity of those contracts are enforced by the system of authority.

The U.S. has a system of law that permits people to control the distribution of their expressions. Tool can decide they don't want their music distributed by iTunes, and the government will enforce that decision. But it's not censorship because iTunes is not expressing any original thought by selling digital copies of Tool's albums. And Tool themselves are free to post their own music online with no restriction.