Rationally Speaking #76 - Crowdsourcing and the Wisdom of Crowds

What are crowdsourcing and the wisdom of crowds and what makes them work? Also, is crowdsoursing ever unethical? And what are the limits to the wisdom of crowds? Plus the hoist's Picks: "The Signal and the Noise: Why So Many Predictions Fail-but Some Don't " in American Life" and The "Phi2Phi" App.