Christopher Mims, writing for WSJ: The internet giants that tout their AI bona fides have tried to make their algorithms as human-free as possible, and that's been a problem. It has become increasingly apparent over the past year that building systems without humans "in the loop" -- especially in the case of Facebook and the ads it linked to 470 "inauthentic" Russian-backed accounts -- can lead to disastrous outcomes, as actual human brains figure out how to exploit them. Whether it's winning at games like Go or keeping watch for Russian influence operations, the best AI-powered systems require humans to play an active role in their creation, tending and operation (Editor's note: the link could be paywalled; alternative source). Facebook, of course, is now a prime example of this trend. The company recently announced it would add 10,000 content moderators to the 10,000 it already employs -- a hiring surge that will impact its future profitability, said Chief Executive Mark Zuckerberg.