Whether it's the Boston Marathon bombings, the cold-blooded murder of 20 schoolchildren in Connecticut, or the definitive American tragedy of this generation, 9/11, one thing is certain – a cottage industry will arise claiming the event was perpetrated or staged by Jews or Israelis for some nefarious purpose. A new study out this week - more than four months after a gunman massacred 20 children and six educators at the Sandy Hook Elementary School in Newtown, Connecticut — finds that a quarter (25 percent) of Americans believe facts about the shooting are being hidden by the government or media and an additional 11% are unsure.
"That's a terrifying number," says Farleigh Dickinson University professor Dan Cassino, who commissioned the poll.
"There is a huge swell of theories claiming [Sandy Hook] was faked," he says. "It's easy to deride these sorts of conspiracy theories, but they seem to have found an audience."
One of the most popular Sandy Hook conspiracy theories blames "Israeli death squads" for the massacre. That claim was given wide play by Iran's Press TV in an opinion piece by Mike Harris, an extremist whose bland-sounding website, Veterans Today, is a clearinghouse of anti-Semitic conspiracy theories.
After the terror attack on the Boston Marathon, it didn't take long for the Internet to light up with conspiracy theories accusing Jews and Israelis of being behind the bombings.
One website, NoDisInfo, published an article just hours after the attack called, 'Zionist Jews Strike Again, Murdering Three in Boston.' (It also blamed the Jews for Sandy Hook).
The line between traditional anti-Semitism and conspiracy theories is fuzzy, as one of the hallmarks of old-fashioned anti-Semitism is the notion that Jews are either involved in, or the reason for, tragic world events. Take Richard Falk, a top official on the UN Human Rights Council known for doubting the "official" version of 9/11 and a long record of anti-Israel extremism. After the Boston bombings, Falk blamed the tragedy on US and Israeli policies.
"As long as Tel Aviv has the compliant ear of the American political establishment, those who wish for peace and justice in the world should not rest easy," he wrote on a foreign affairs website.
The Anti-Defamation League (ADL) called it "outrageous that the UN Human Rights Council continues to support such a wildly conspiratorial and highly biased extremist as a reliable 'expert.'" It said the organization's affiliation with Falk "only serves to undermine its credibility."
But why are Jews so often the subject of conspiracy theories?
Cossini says Jews are blamed for misfortunes today for much the same reason they've been blamed for centuries.
"There is a perception of Jews as the Other – a part of society, but still somehow foreign. Couple that with resentment over Jewish success in certain areas of society, and they'll be blamed for things that are otherwise just ineffable."
Michael Barkun, a Syracuse University professor emeritus and author of "A Culture of Conspiracy: Apocalyptic Visions in Contemporary America," says conspiracy theorists are guided by three main beliefs: nothing happens by accident; everything is connected; and nothing is as it seems.
"If that's your view of the world, then appearances can't be trusted. There has to be some hidden reality and linkings that have to be exposed," he says.
According to Mark Potok of the Southern Poverty Law Center, "Conspiracy theories are the way weak minds deal with complex situations." He calls America "probably the most conspiracy-oriented country in the world" and says the problem has gotten worse in recent years.
Why? The Internet.
"The Internet is the perfect place to incubate conspiracy theories," says Rabbi Abraham Cooper of the Simon Wiesenthal Center. "Old ones like the Protocols of the Elders of Zion and new ones like the Zionists and the CIA engineered 9/11."
He says many conspiracy theories of the past died out as those who promulgated them tended to be isolated and unable to reach larger audiences.
Cassino agrees, saying, "the Internet plays a huge role in the promulgation and acceptance of these theories."
"In the past, if you thought, for instance, that the Sandy Hook shootings didn't really happen, you were on your own. You probably wouldn't know anyone else who thought the same way, and wouldn't want to share your thoughts with those who might not agree with you. Today, though, it's easy to find communities of like-minded people on the Internet, and this creates a false consensus effect: there's a whole group of people who agree with me, so it must be true."
He says another crucial difference between then and now is that there is no simple way to tell the difference between credible and non-credible information online.
"If you saw one story in a newspaper and another in a handwritten scrawl on a napkin, you'd be more likely to believe the newspaper. On the Internet, though, the story put out by real journalists from a credible source and the story put out by the tinfoil hat crowd look exactly the same."
There's a debate in the traditional media about the merits of publicizing outlandish conspiracy theories. CNN's Anderson Cooper, for example, denounced at length a Florida Atlantic University professor named James Tracy who questioned media accounts of Sandy Hook. Cooper, like others in the industry, believes debunking myths early in their life cycle can prevent them from spreading.
However, Dartmouth College professor Brendan Nyham, criticized Cooper in the Columbia Journalism Review for risking the spread of Tracy's false claims by drawing attention to them.
"Tracy is still an obscure figure of no particular influence. His views deserve little attention, but unfortunately, Cooper took the bait, seizing the opportunity to righteously denounce a crackpot on air," he wrote.
Nyham doesn't believe all conspiracy theories should be ignored by the press. Rather, he says the media should cover and debunk myths already in widespread circulation such as the notion that President Obama wasn't born in the US (called "birtherism"). He also warns mainstream media outlets on the political right and left against covering bogus claims from the opposite fringe in order to paint their political opponents "as extremists or cranks."
"This freak show strategy could be profitable," he said. "But it might also provide oxygen to conspiracy theories that would otherwise fizzle. Don't feed the trolls!"