It's true. Don't believe everything you read on the Internet.
In fact, according to a study by media researchers, many news organizations fail to do enough to separate fact from fiction, and often help unverified rumors and reports to go viral online.
"Rather than acting as a source of accurate information, online media frequently promote misinformation in an attempt to drive traffic and social engagement," said the study led by Craig Silverman, a research fellow at the Tow Center for Digital Journalism at Columbia University.
While news organizations have always dealt with unverified information, practices at some websites may accelerate the dissemination of fake news, said the report, "Lies, Damn Lies and Viral Content."
"Many news sites apply little or no basic verification to the claims they pass on. Instead, they rely on linking-out to other media reports, which themselves often only cite other media reports as well," the study concluded.
Fake stories are often sexier or more interesting than the real ones, and as such get wider dissemination, Silverman said.
"The extent to which a fake news article can get traction was surprising to me," Silverman told AFP.
Examples cited in the study were rumors spread on Facebook and Twitter that an Ebola patient had been identified in Britain, and another that the disease had been found in Richmond, Virginia. Both reports were untrue.
- 'Rehana, ISIS slayer' -
In another case, a story about a Kurdish woman dubbed "Rehana the ISIS slayer," or the "Angel of Kohane" purported to have killed 100 Islamic fighters, turned out to have no basis in fact even though reports about her spread for weeks last October.
The researchers traced the story to a tweet from Indian journalist and activist Parwan Durani, who published the woman's picture on Twitter and asked people to retweet it.
Stories of her exploits -- and reports of her death -- were picked up widely by news outlets "but seemed entirely based on falsities," Silverman's report said.
"The simple story of the attractive Kurd who killed dozens of ISIS fighters is a powerful wish rumor. Add in a compelling image and it's perfect for propagation on social networks. The result is that most of us will never know the woman's true story -- and the press bears a level of responsibility for that."
Silverman said that even if much of the fake news is spread by "new media" or tabloid journals, the traditional or "quality" journalism outlets often sit by, allowing rumors to gain traction.
"When (fake) information is out there and websites are covering it, there is an imperative on the part of news organizations to look at it, flag it for readers and tell them what we know and what we don't know," Silverman said.
"If we remain silent, the ones who win are the mindless propagators."
And many news organizations fail to follow up when a false report is debunked, the report said: "The explosive claim that ISIS fighters had been apprehended at the US-Mexico border was refuted within 24 hours and yet only 20 percent of news organizations that wrote an initial story came back to it."
- A 'disturbing trend' -
The findings show "a very disturbing trend," said Bill Adair, a Duke University journalism professor who in 2007 founded the fact-checking website PolitiFact.
"It's particularly disturbing when journalists pass along things without knowing whether they are true or not."
Because of the fast-moving nature of Twitter an other social media, Adair said that "many people including journalists feel that if it's tweeted, it's out there and it's fair game. But news organizations have always had an obligation to check out what they pass on."
Sometimes the sheer number of repetitions of false information makes people believe something is true, the researchers said.
One example of this is the oft-repeated claim that the Obamacare health plan includes "death panels" which decide whether a person can receive treatment.
"Anyone who repeated it -- even when trying to debunk it -- further implanted it and its negative connotations in people's minds," the report said.
Nikki Usher, a George Washington University professor specializing in new media, said previous research has shown that repeating false information makes it more believable, "but what is different now is the speed with which rumors can unfold."
The Internet's "crowdsourcing" ability can often bring the truth out, but cannot entirely correct the problem, said Silverman, who also operates the @emergentdotinfo Twitter feed that tracks online rumors.
"Over time the truth emerges, but the corrections don't tend to be as viral or get as widely distributed. And they don't always reach the same people," he said.
"I am a believer in the value of the crowd, but the truth is often far less interesting and shareable than the lie."