Do Trolls Eat Spam?
What's the difference between trolling behavior and plain old spam? It's a subtle distinction, but critical to understanding when combating either. We classify as spam those communications that are indiscriminate, unwanted and broadcast to a large audience.
Fortunately, those same characteristics that mark a communication as spam—its indiscrimination, its lack of relation to the conversation at hand, its overtly commercial appeals—also make it stand out. You're probably easily able to identify spam on sight, after just a quick initial inspection. We can teach these same tricks to machines. Although spammers constantly change their tactics to evade detection, spam can generally be detected by machine methods.
Trollish behavior, however, is another matter altogether. Trolls may not be motivated by financial motives—more likely, they're craving attention, and motivated by a desire to disrupt the larger conversation. (See egocentric incentives.) Trolls quickly realize that the best way to accomplish these goals are by non-obvious means. An extremely effective means of trolling, in fact, is to disguise your trollish intentions as real conversation.
Accomplished trolls can be so subtle that even human agents would be hard-pressed to detect them. In Chapter 7, we discuss a kind of subtle trolling in a sports context: masquerading as a fan of the opposing team. For these trolls, presenting themselves as faithful fans is part of the fun—then it's all the more disruptive once they started to trash-talk "the home team."
How do you detect for that?
It's hard for a human, and nigh-impossible for a machine. It is, however, easier to do with a number of humans. By adding consensus, and reputation-enabled methods, it is easier to reliably discern trollish behavior from sincere contribution to the community. Because reputation systems, to some degree, reflect the tastes of the community, they also have a better-than-average chance at catching behavior that transgresses against those tastes.