The article does highlight that there is an interesting game-theoretic issue here. Given a crowd of N people, with such-and-such dynamics, is the damage that 1 person can do bounded or unbounded? Is it better to control the number of bad actors, or to restrict the actions any one actor may take?

I'm un-aware of results in this area, but as online communities become more important, and bots become more sophisticated, the stakes will raise. Having some community models, analysis tools, or heuristics, would be very interesting.

Did you read the whole article?

The studies cited point to this being the case in a lot more than just one instance.

Even 'successful' crowdsourced efforts like Wikipedia are scarcely without their problems.