Really interesting and thought-provoking discussion about the possible ethical and moral problems that services like Mechanical Turk might create. Not all doom-and-gloom, and with good examples of problems beyond the obvious "it's really poorly paid, so is like a sweatshop" concern.
We (the tech community in particular, along with wider society) need to have more of these sorts of discussions, and at least with this it's happening fairly early on in the adoption of the new technologies.