From an article by Richard W Rahn
"Assume you are a scientist and have been given a major financial grant to prove that the mythical unicorn really did exist. You know that as long as you can demonstrate some progress in showing the unicorn might have existed, your financial grant will be renewed each year, provided some other scientist does not come out with substantial evidence that the unicorn could not have existed. Under such conditions, you would have a very strong incentive to disregard much of the evidence that the unicorn could not have existed and each year provide only the data that could demonstrate that the unicorn might have existed. You also would have a very strong incentive to attack any scientist who raised serious questions or provided evidence that the unicorn could not have existed. You even might go so far as to refer to them with the disparaging term 'unicorn deniers' and attempt to use your influence with other scientists who also are receiving grants dependent on the existence of the unicorn to try to prevent the unicorn deniers from publishing their findings in well-regarded scientific journals. The recently released e-mails (by whistleblowers or hackers, depending on your prejudice) between some of the best-known scientists behind global warming showed that they succumbed to the all-too-human tendency to protect their turfs and pocketbooks, despite the evidence."