If a man tells himself a lie over and over again, eventually he will begin to believe it as fact. When the lie is something that fundamentally alters his view of reality, it can turn dangerous.

The chemtrail conspiracy theory is a well-covered phenomenon around these parts, and every time I or someone else writes a story trying to debunk the ridiculous myths surrounding this ugly bit of anti-science, the hardcore believers jump in and explain why they know The Truth and everyone else is being paid to lie about it.

So when I heard this afternoon that the Las Vegas shooter was into the chemtrail conspiracy theory, my first two reactions were 1) oh, that figures and 2) oh, man.

The chemtrail conspiracy theory and its relatives are far from mutually exclusive. The folks who believe that the trails of cirrus clouds that form from the warm, moist exhaust that follow behind high-flying aircraft are really chemicals being sprayed on us by the government usually believe in the whole package: the United Nations is controlling the world; the Jews control everything, too; vaccines are a plot to cull the population and make your kids autistic; Obama is not an American citizen and his group of thugs are out to take your guns; the government is rounding up train cars to ship people to FEMA reeducation camps a la Nazi Germany; on and on and on.

Each individual theory on its own is seemingly harmless, but belief in one acts like a gateway drug that leads to harder conspiracies, and the more a man convinces himself that the world is out to get him, the more prone he is to lashing out. The chemtrail conspiracy theory isn't what drove that man and his wife to shoot three people and then each other in Las Vegas yesterday, but it's symptomatic of a larger problem where people are seeing shadows that aren't there, and acting out in incredibly dangerous ways.

Mental health issues aside, we need to confront and defuse the growing sway that conspiracy theorists have on society. Chemtrails do not exist, the United Nations is not taking over the world, Obama is not grabbing your guns, vaccines are not a plot to cull the population, and you're not going to be sent to a concentration camp. The hysterics have got to stop. The anti-science and anti-reality junk theories being peddled as fact are killing people.

[Image via AP]