Inflammatory stories masquerading as real news pose a particularly toxic threat in Asian countries with long-standing religious and ethnic divides, but promises by some regional leaders to tackle the problem carry equal menace.
Borrowing from US President Donald Trump's political playbook, government heads with an authoritarian streak are using the mantra of "fake news" to shield themselves from negative media coverage, and push legislation that critics say is aimed more at stifling dissent than punishing fabrication.
The problem they profess to be addressing is a genuine one.
Internet penetration is now so extensive -- even in the poorest areas -- that fake stories dressed up as fact can go viral on social media overnight and reach massive audiences with often dire consequences.
In India last year, seven people were killed by a mob after a false story spread on WhatsApp that they were child-traffickers, while in Myanmar, doctored photos and bogus reports shared on Facebook have fuelled the persecution of Rohingya Muslims.
A number of Asian leaders have tapped into the resulting public concern and launched campaigns that claim to target malign rumour-mongers but, experts say, actually serve to turn the screws on critical media and political opponents.
"This vague notion of 'fake news', which has been used and abused by US President Donald Trump, is a boon for governments who want to muzzle overcurious independent voices," Daniel Bastard, head of the Asia-Pacific desk at Reporters Without Borders (RSF), told AFP.
Philippine President Rodrigo Duterte -- who once memorably warned media that "just because you're a journalist, you're not exempted from assassination" -- has regularly accused news outlets critical of his deadly war on drugs of peddling fake news.
He has openly attacked a top newspaper and broadcaster, while the biggest target of the media clampdown has been news website Rappler.
Philippine authorities have cancelled its corporate licence over claims the outlet violated foreign ownership laws and filed a criminal complaint over an alleged failure to pay taxes on bonds it issued.
- Pushing legislation -
In Cambodia, authoritarian Prime Minister Hun Sen has openly praised Trump's "Fake News Awards" -- handed out in January by the president to his usual targets, including CNN and The New York Times -- and lobbed the "fake news" charge at his own media critics.
It has helped provide ammunition for his government's sweeping assault on independent media in recent months, with the widely-respected Cambodia Daily newspaper shuttered after being hit with a huge tax bill and dozens of independent radio stations closed.
Some countries are seeking to legislate against fake news, sparking concerns that the laws will be used to stifle dissent.
Malaysia enacted a law this month that punishes publishers of false reports with up to six years in jail, which observers say is a clear bid to stifle criticism of scandal-hit Prime Minister Najib Razak before elections next month.
Singapore has been holding parliamentary hearings to consider measures, including laws, against what the government terms "deliberate online falsehoods" while the Philippines is considering legislation that could see publishers of fake news punished with up to 20 years in jail.
Clarissa David, a media expert at University of the Philippines, warned that any such law in the Philippines may become "a tool for censorship" that could be used to "silence legitimate news organisations from covering stories that are unfavourable to groups in power".
Michael Vatikiotis, a Southeast Asia expert, said that legislating against fake news "puts journalists in deeper peril".
"Unlike normal justifications for curbing media freedom, fake news is a broad, catch-all definition that is wholly subjective," Vatikiotis, an author and former journalist, told AFP.
- Alarm in Europe -
Still, fake news is undoubtedly a real threat and has sparked particular alarm in Europe where governments are worried that Russia may try to meddle in elections, following allegations that Moscow sought to tilt the 2016 US poll in Trump's favour.
Germany has passed a law threatening social networks with fines if they do not remove bogus reports and hate speech while Brussels is working on a Europe-wide plan to tackle fake news online.
But media rights groups are against legislation, arguing instead for the press to follow a strict set of standards they set themselves, and for social media giants such as Facebook to come up with responsible policies to stem the flood of misleading information.
RSF's Bastard warned that the idea of social media companies policing themselves could pose as many problems as governments passing laws, however.
"Will (Facebook CEO) Mark Zuckerberg decide what is 'real' or 'fake'?" he said.
"Just as we have big reservations when states want to control the 'realness' of news through legislation, we don't want corporations to decide it without any transparency."