I would completely agree with what you said about the rights of the private companies if Amazon was a regular market player. But even you qualified above statement. Even though Amazon is not really a monopoly, it is pretty close for small scale book selling. That is, it has such a dominant market share that its decision not to sell a book can be a death sentence for a small book publisher. Thus they should be super careful when culling titles by content -- next time they might pull <insert your favorite hot topic> and there will be no recourse either.