Odds are, you've heard of the "tragedy of the commons." (If not: Let Google be your guide.) The (contemporary) source of the idea is an article written by ecologist Garret Hardin some time ago, laying out the seemingly logical proposition that (at base) -- people in a community will inevitably abuse a shared resource in order to try and maximize their personal use of it, such that the shared resource will eventually run out or be otherwise denuded.
Although in my own research, I've certainly read of cases where that did happen, it certainly is far from true that that always happens, or that the only ways to prevent it are: a) government coercion/restricted access, or b) complete privatization. He argues that one cannot rely on conscience or cooperation to regulate the wise use of a commons, as selfish people will inevitably exploit it.
We all know cases where such exploitation does happen, again, but it certainly isn't an "inevitable consequence" as Hardin implies. (A mentor of mine has re-phrased Hardin's proposition as "The tragedy of the privately owned sheep" -- based on the case Hardin used as an example, that of English peasants herding sheep with a commons providing forage for the sheep. Of course, if the sheep were raised in common for the village, it would again not be in their interest to denude the commons, theoretically bringing the system back in balance -- and certainly, it's easier to tell who is eating extra sheep and thus "conscience" and social pressure seem more likely to rule in that case. But I digress.)
Although the argument has grown considerably more complicated since Hardin (and I suspect before as well -- he was hardly the first to think of this), the raison d'etre of this blog post is this article here, pointing out that as written, Hardin's piece offered no actual proof, real-life context, or other essential elements of scientific reasoning, yet it has been hugely influential and widely quoted. The author implies that this is because it could be used to justify pre-existing prejudices, which it certainly did so for Hardin, who himself was something of a eugenicist and rather worried about the population growth of the poor masses (rather than the population growth of the huge, resource-chomping-like-it's-candy wealthy few). Anyway. Read. Tchau.