This item from Wired’s blog describes the work of social networking software creator Valdis Krebs:
According to Krebs… a social network creates a pseudo-truth that overrides real, objective truth [and] help[s] explain why pack mentality dominates the web.
Using the current election as a model, Krebs says that the internet does not bring people with different ideas together. Instead, people seek out groups with similar ideologies, which makes them less prone to objective, flexible thinking. And no matter how extreme the idea, there’s someone out there on the web who will build a forum around it.
Psychological research has shown that when people find their “political mirrors,” they immediately build clusters around their ideas. This is why politicians’ use of confrontational language like, “You’re either with us, or with the terrorists,” seems to work.