"So-called deniers, such as those who deny that the Jewish holocaust of World War II ever occurred, believe themselves to be skeptics. On the other hand, true believers, such as UFO enthusiasts, will often portray those skeptical of their beliefs as being closed-minded deniers."
"With a fuzzy border between skepticism and denial, how do we tell the difference? Adding to the difficulty, individuals or groups may combine legitimate skeptical arguments with denial strategies."
"Identifying underlying motivation is important to understanding the phenomenon of denial and the psychology of deniers."
"With sufficient complexity, almost any desired conclusion can be supported if only a selective subset of the data is considered."
"The most sophisticated of my opponents utilized many of the arguments and tactics of skeptics, including accusations of logical fallacies, having belief which exceeds the evidence, and being a motivated true-believer. At times I even found myself using arguments that were strangely reminiscent of true believers I have debated on other topics."
http://www.theness.com/skepticism-and-denial/