Monopolies are not natural. There are only two ways that monopolies form in a free market. Either the firm is the first on the scene (first-comer advantage) or they are the only firm in a given area providing a product or service. Monopolies are prohibitively expensive to maintain for any significant period of time - unless you control all the guns or know the guy who does (government). Absent a state, a would-be monopolist would have to continually expend vast sums of resources to buy out competitors or operate at continual losses to try to run them out of business. Regulations on industries are numerous and all over the place, so I'm not sure what state regulations you're talking about. There are tens of thousands of regulations in the US federal ledger alone covering almost every conceivable kind of market transaction, and every year more are added.
I never said the current system doesn't work. It does, and I said as much; the state providing security proves it can be done. It's vastly inferior to a private solution and unethical for the reasons I mentioned, without even mentioning the economic calculation problem.
Monopolies most certainly are natural. There are many essential industries in which private companies are never the first to operate because the initial fixed costs are too high. No private company has ever created a rail network or a national grid. Any situation in which supply is sparse and a company has control over resources through exclusive supplier agreements, intellectual property rights etc. Monopolies are natural, and states have to intervene to stop them from forming. For example, here in the UK the government recently had to block a merger between O2 and Three because the result would be that one economic entity would controll too great a share of the market.
Are you kidding me? Rail networks and energy grids were created by private companies first prior to them being nationalized. I never said monopolies don't happen absent the state, so you can take that strawman and torch it. What I did say, however, is that they are unsustainable and will not last, because the costs associated with maintaining an actual monopoly are astronomical and continue to increase over time. Every regulation passed on an industry increases the costs to enter said industry, which reduces competition. Less competition = more market share for existing firms that can bear the brunt of those costs. There's no way you can argue against this; regulations increase costs, and increased costs put a downward pressure on new firms entering the marketplace, which reduces competition.