But come on, I don't want to argue your specific example -- it is clearly meant to be ridiculous. Real-world natural monopolies tend not to last very long without government support (or a strained and narrow definition of what their market is that ignores substitution), particularly if they aren't serving their customers well. The exceptions that you can think of are just that, exceptions. And even at that, I can't think of very many good counter-examples. Microsoft is perhaps the best case, but even there, by strangling the desktop they arguable accelerated the move towards innovation in the cloud (so that we could get around them). You can see this effect even as early as 1995, when PG started Viaweb as a webapp in part because he didn't want to develop for Windows. Substitution is always the death of an otherwise strong monopoly. The government didn't breakup Microsoft, but no one is worried about them these days anyway (http://www.paulgraham.com/microsoft.html).
You keep falling back on what is or is not lawful. I'm not interested in debating that. It takes an expensive discovery process and a lot of lawyers and judges to determine what is or is not lawful in a complex real-world situation. In my book, lawful does not equal moral, and unlawful does not equal immoral. I find morality more meaningful to talk about.
As for the terms I use, they simply reflect my moral approach to the problem. If you can imagine a scenario in which taking the fruit of a peaceful individual's labor from him or her by force is moral and just, then you're starting from different moral axioms than I am.