Conversation so far:
Why did he start this?
cascades" of faulty information within groups that may ultimately lead to violence.
In this article they wrote, "The existence of both domestic and foreign conspiracy theories.
What year was this?
2008.
What is this in?
paper.
Who wrote it?
Sunstein co-authored a 2008 paper with Adrian Vermeule.
What is the name of the paper?
Conspiracy Theories.
What is it about?
Government agents (and their allies) might enter chat rooms, online social networks, or even real-space groups.
Any other cool facts?
attempt to undermine percolating conspiracy theories by raising doubts about their factual premises, causal logic or implications for political action..
What else do they question?
They refer, several times, to groups that promote the view that the US Government was responsible or complicit in the September 11 attacks as "extremist groups..

Question: What do they say to this?
Self-contained rewrite: What do the US Government say to groups that state the government was responsible for the September 11 attacks?