Groupthink is a term coined by psychologist Irving Janis in 1972 to describe one process by which a group can make bad or irrational decisions. In a groupthink situation, each member of the group attempts to conform his or her opinions to what they believe to be the consensus of the group. This results in a situation in which the group ultimately agrees on an action which each member might normally consider to be unwise.
Definition taken from http://www.co-intelligence.org/
Groupthink in the blogosphere
1. The Anti-Wisdom of Crowds
James Surowieki is the author of the landmark book on the benefits of aggregate decision-making, The Wisdom of Crows. But in this interview and podcast he stresses the pitfalls of it.
2. The Echo Effect of the New Gatekeepers
The New Gatekeepers is the name given to the new elite of the blogosphere, the most influential "A-listers", who are the most influential in settng the terms of a debate. From Tristan Louis at http://www.tnl.net/blog/entry/The_New_Gatekeepers
The Blogosphere created "a sea of endless information that our current brains are unable to cope with and this is where a level of re-intermediation came in: because there was so much content being created, the blogosphere needed to have some guides that would help people navigate to what was considered good. In a word, we created some new gatekeepers that we now know at the blogging A-list (and, to some extent, an equivalent B-list and C-list). Membership on it is limited and many have said that the way to disprove the power of the A-list is by showing that new members have appeared on it: what few are willing to admit is that the new members are really only allowed as one of these groups if they are vetted by enough existing members. This creates a self-fulfilling cycle where members of the small club of "blogs that matter" get to shape the agenda ... Because the group is relatively small, it has gained an increased importance in terms of defining what matters. Algorithmic solutions like Memeorandum (or even Google's PageRank) help reinforce an echo effect from such small groups. Because the groups are within a category (whether it is politics or technology, the two prominent categories in that space), the impact of an individual can be increased through cross-linking between members of the blogging elite." (http://www.tnl.net/blog/entry/The_New_Gatekeepers)