The posts from DemocraticUnderground seem to be focused on the Lockean Proviso; that property may be owned by individuals "so long as there is as much and as good." According to many of them, it is acceptable if there are high profits as long as the product produced is not wanted by many (i.e. yachts). If the product is a "necessity," (e.g. oil, food, airline travel?) then profits should be low (or non-existent).
The Lockean Proviso creates a major problem: when a good is not scarce, then it may be owned; whereas, if the good is scarce it may not be owned. Therefore, the DemocraticUnderground allows high profits on yachts, which are to them non-scarce (i.e. not needed) and would not allow high profits on necessary goods. Taken to its logical conclusion, the Lockean Proviso would allow the ownership of air (a non-scarce good - although even this is debatable given the growing global warming hysteria) and not much else. The ownership in all other goods which are by definition scarce, should then not be owned and the market would not be able to function.
In 1650, the Lockean Proviso may not have made much difference, as he was mostly referring to land ownership and the fact that the New World increased the land mass available substantially (almost infinitely relative to the population of England). It also may have been politically appealing. However, it is still a major subject in law and treated as an undeniable premise. However, it seems to me that modern economics, especially Austrian econ, has proven this premise demonstrably and absolutely false. Too bad the legal community has not gotten this message.