I completely understand and agree that under normal circumstances, a monopoly cannot be formed outside of government regulation (at least not one which exploits the consumer), but I have been wondering lately about how the free market would keep large companies from monopolizing resources needed for production in a particular industry. It seems that the more limited a resource is, the easier it would be for a company to take a larger percentage of the resource as it grows, until it becomes impossible for legitimate competition to rise up. Of course, in most cases there are likely substitutes for the resource or good being produced to counter this problem, but it seems that there would be cases where a substitute would not be viable. With no regulation, what forces would keep this situation under control?