I don't particularly see a problem if someone wants to corner the market on pork bellies. It's tasty, but entirely non-essential.

Corner the market on water? One of the most common compounds on the planet earth?

The price of metered water in San Francisco is $5.45 for 748 gallons. I am having difficulty imagining how any conceivable price increase could either deny the poor enough water to drink, cook and shower or open the door to a monopolist to seize control of all of it.

Maybe. I'd have to think about it. Water is singularly unlike any other commodity, though, because of its positive external effects on society. As an example I give you sanitation. Do you want to ride on a bus full of people who do not all have running water at home, for washing their hands? Probably not.

The most obvious case is patented drugs. As that's the point of patents in the first case.