It's an astonishing claim: The tornado that ravaged Joplin, Mo., last Sunday, killing at least 125 people, was not a random act of nature but the result of an obscure military-backed research program in Alaska that shoots radio waves into the upper atmosphere.
Here's another one: The shooting rampage in Tucson last January that killed six people and wounded 13, including Rep. Gabrielle Giffords, was an elaborate government hoax that used actors to portray the victims.
And there is this: Osama bin Laden is still alive, and the raid in which daring Navy SEALs shot him dead on April 29 was fabricated to improve President Obama's chances of winning re-election.
These are three of the bogus new conspiracy theories flying across the Internet, advanced by believers who insist the evidence to support them could not be any clearer.
"Don't know about the rest of you, but I'm telling everyone I know and don't know (sales clerks, bank tellers, waiters, etc.) about the weather manipulation," a YouTube poster named "thegreenieye" wrote, responding to a video that claims last month's devastating tornado in Tuscaloosa, Ala., also was caused by the atmospheric research in Alaska.
"99.5 [percent] of people are completely unaware of this," thegreenieye wrote. "Tell everyone you know (and don't know) about it. The masses need to be informed!"
Conspiracy theories are not new, but there has been an explosion of them recently.
Jon Kay spent 2 ½ years interviewing conspiracy theorists, attending their conventions and surfing their websites to write the just-published "Among the Truthers: A Journey Through America's Growing Conspiracist Underground."
Kay initially intended to explore the so-called "truther" movement, which makes the slanderous claim the 9/11 attacks were engineered by the U.S. government, and approved by then-President George W. Bush and Vice President Dick Cheney, so the U.S. could invade Iraq and Afghanistan and curtail civil rights.
But once Kay entered the conspiracy rabbit hole he discovered a world of extreme paranoia -- a multitude of conspiracy theories nourished by the Internet and fueled, in part, by anxiety caused by tough economic times.
"I was surprised by how prevalent they are," said Kay, the op-ed editor of the National Post newspaper in Canada. "What was shocking to me when I started interviewing people was that once someone bit on one conspiracy theory, they would enter this subculture and subscribe to 10 others."
That subculture now includes the head-spinning claim that the deadly rampage in the parking lot of a Tucson supermarket on Jan. 8 was not a shooting but an event staged by the government.
The New York Times, which first reported the Tucson conspiracy theory, said believers have confronted at least one victim and asked for evidence he had been shot.
A Texas-based website making the allegation said it has been investigating to determine if the media lied about the rampage to push an "anti-gun" agenda.
"What I found shock [sic] me to the core of my being," the site's operator said in a posting.
There are several conspiracy claims blaming atmospheric research in Alaska for a series of national disasters, including the tornadoes in Joplin and in Tuscaloosa, the catastrophic earthquake in Japan and last year's earthquake in Haiti.