What an extremely scientifically flawed study.
Using online commenters on news stories as a study group introduces bias into the survey. The researchers also failed to mention what particular news stories they included and why, and from which websites these comments were plucked. A random sample would give a much more accurate portrayal of the relative sanity of "conspiracy theorists" compared to "government dupes". By the way, you think the authors of the study stereotype much?
"In survey sampling, bias refers to the tendency of a sample statistic to systematically over- or under-estimate a population parameter. Bias often occurs when the survey sample does not accurately represent the population. The bias that results from an unrepresentative sample is called selection bias".
"Voluntary response bias. Voluntary response bias occurs when sample members are self-selected volunteers, as in voluntary samples. An example would be call-in radio shows that solicit audience participation in surveys on controversial topics (abortion, affirmative action, gun control, etc.). The resulting sample tends to over represent individuals who have strong opinions".
"Random sampling is a procedure for sampling from a population in which (a) the selection of a sample unit is based on chance and (b) every element of the population has a known, non-zero probability of being selected. Random sampling helps produce representative samples by eliminating voluntary response bias and guarding against undercoverage bias. All probability sampling methods rely on random sampling".
http://stattrek.com/survey-research/survey-bias.aspx