I think the problem is when companies get so big that they have a monopoly or form big trusts and other cartels they are able to shut out any of the competition and effectively shut down the free market. I think we've had a history of breaking up big trusts and monopolies in the name of saving capitalism, at least our form of it. but, we are a lot more socialist that most people think just look at our "progressive tax rate" system, which is, from what I understand, one of the first tenets of Marxism. I'm not saying that is good or bad its just fact.