Monopolies are not the natural state of a market. Quasi-monopolies can emerge in industries with very large economies of scale, but even then they evolve and who was #1 25 years ago rarely is still #1 today. Monopolies exist when the barriers to entry are so high that it makes no economic sense for a new competitor the enter the market. That almost always results from government intrusion -- not a free market. Consumers are almost always willing to consider something new. They might like it, or not -- but it is not consumer behavior (markets) that creates monopolies -- and even if it did, that would reflect the consumers' (market) preference, and such preferences are notoriously fickle. These monopolies are thus not long lived. As soon as you talk about 'policing,' you reveal yourself to still embody a smidge of statist in your anarchist philosophy. Few of us, if any, can realistically maintain that we are 100% anything -- libertarian, communist, free-market capitalist, whatever. There are always some things that a free market might not be the best solution to. The Founders identified some they thought fit the bill -- the military and securing the nation's borders, to name a couple. But we should seek to see that only in those areas where there is a clear and compelling reason to give a government power, that we do so. For me anyway, 'policing monopolies' is not one of them. YMMV...