Recent quotes:

How a lone hacker shredded the myth of crowdsourcing — Backchannel — Medium

“Myself and others in the social sciences community tend to think of such massive acts of sabotage as anomalies, but are they?” wondered Cebrian. To settle the question, Cebrian analyzed his (and other) crowdsourcing contests with the help of Victor Naroditskiy, a game theory expert at the University of Southampton. The results shocked him. “The expected outcome is for everyone to attack, regardless of how difficult an attack is,” says Cebrian. “It is actually rational for the crowd to be malicious, especially in a competition environment. And I can’t think of any engineering or game theoretic or economic incentive to stop it.”