Read the paper. Here are some relevant excerpts.
Many millions of people hold conspiracy theories; they believe that powerful people have worked together in order to withhold the truth about some important practice or some terrible event. A recent example is the belief, widespread in some parts of the world, that the attacks of 9/11 were carried out not by Al Qaeda, but by Israel or the United States. Those who subscribe to conspiracy theories may create serious risks, including risks of violence, and the existence of such theories raises significant challenges for policy and law.
As we shall see, an understanding of conspiracy theories has broad implications for the spread of information and beliefs; many erroneous judgments are a product of the same forces that produce conspiracy theories, and if we are able to see how to counteract such theories, we will have some clues about how to correct widespread errors more generally.
We bracket the most difficult questions here and suggest more intuitively that a conspiracy theory can generally be counted as such if it is an effort to explain some event or practice by reference to the machinations of powerful people, who have also managed to conceal their role. This account seems to capture the essence of the most prominent and influential conspiracy theories. Consider, for example, the view that the Central Intelligence Agency was responsible for the assassination of President John F. Kennedy; that doctors deliberately manufactured the AIDS virus; that the 1996 crash of TWA flight 800 was caused by a U.S. military missile; that the theory of global warming is a deliberate fraud; that the Trilateral Commission is responsible for important movements of the international economy; that Martin Luther King, Jr., was killed by federal agents; that the plane crash that killed Democrat Paul Wellstone was engineered by Republican politicians; that the moon landing was staged and never actually occurred.
Of course some conspiracy theories, under our definition, have turned out to be true. The Watergate hotel room used by Democratic National Committee was, in fact, bugged by Republican officials, operating at the behest of the White House. In the 1950s, the Central Intelligence Agency did, in fact, administer LSD and related drugs under Project MKULTRA, in an effort to investigate the possibility of “mind control.†Operation Northwoods, a rumored plan by the Department of Defense to simulate acts of terrorism and to blame them on Cuba, really was proposed by high-level officials (though the plan never went into effect).13 In 1947, space aliens did, in fact, land in Roswell, New Mexico, and the government covered it all up. (Well, maybe not.) Our focus throughout is on false conspiracy theories, not true ones.
What can government do about conspiracy theories? Among the things it can do, what should it do? We can readily imagine a series of possible responses. (1) Government might ban conspiracy theorizing. (2) Government might impose some kind of tax, financial or otherwise, on those who disseminate such theories. (3) Government might itself engage in counterspeech, marshaling arguments to discredit conspiracy theories. (4) Government might formally hire credible private parties to engage in counterspeech. (5) Government might engage in informal communication with such parties, encouraging them to help. Each instrument has a distinctive set of potential effects, or costs and benefits, and each will have a place under imaginable conditions. However, our main policy idea is that government should engage in cognitive infiltration of the groups that produce conspiracy theories, which involves a mix of (3), (4) and (5).
We suggest a distinctive tactic for breaking up the hard core of extremists who supply conspiracy theories: cognitive infiltration of extremist groups, whereby government agents or their allies (acting either virtually or in real space, and either openly or anonymously) will undermine the crippled epistemology of those who subscribe to such theories. They do so by planting doubts about the theories and stylized facts that circulate within such groups, thereby introducing beneficial cognitive diversity.
After 9/11, one complex of conspiracy theories involved American Airlines Flight 77, which hijackers crashed into the Pentagon. Some theorists claimed that no plane had hit the Pentagon; even after the Department of Defense released video frames showing Flight 77 approaching the building and a later explosion cloud, theorists pointed out that the actual moment of impact was absent from the video, in order to keep alive their claim that the plane had never hit the building. (In reality the moment of impact was not captured because the video had a low number of frames per second.62) Moreover, even those conspiracists who were persuaded that the Flight 77 conspiracy theories were wrong folded that view into a larger conspiracy theory. The problem with the theory that no plane hit the Pentagon, they said, is that the theory was too transparently false, disproved by multiple witnesses and much physical evidence. Thus the theory must have been a straw man initially planted by the government, in order to discredit other conspiracy theories and theorists by association.
We suggest a role for government efforts, and agents, in introducing such diversity. Government agents (and their allies) might enter chat rooms, online social networks, or even real-space groups and attempt to undermine percolating conspiracy theories by raising doubts about their factual premises, causal logic or implications for political action.
Infiltration of any kind poses well-known risks: perhaps agents will be asked to perform criminal acts to prove their bona fides, or (less plausibly) will themselves become persuaded by the conspiratorial views they are supposed to be undermining; perhaps agents will be unmasked and harmed by the infiltrated group.
Some conspiracy theories create serious risks. They do not merely undermine democratic debate; in extreme cases, they create or fuel violence. If government can dispel such theories, it should do so. One problem is that its efforts might be counterproductive, because efforts to rebut conspiracy theories also legitimate them. We have suggested, however, that government can minimize this effect by rebutting more rather than fewer theories, by enlisting independent groups to supply rebuttals, and by cognitive infiltration designed to break up the crippled epistemology of conspiracy- minded groups and informationally isolated social networks.