You know something is seriously up when a social media company buys full-page ads in old-fashioned newspapers.

WhatsApp's campaign ahead of India's mammoth election also included highly produced spots on television and radio. The message to millions of Indians, across the various platforms: "Share joy, not rumours."

The messaging app's public outreach was just one plank of a fledgling, multi-tier effort in India to try and contain the round-the-clock avalanche of fake news that has in the past cost people their lives by sparking violence and even lynchings.

Government, civil society, and journalists have also joined an effort to fight back against falsehoods that could alter the results of the vote, which runs from April 11 to May 19.

Pressured repeatedly to act, WhatsApp — which is owned by tech giant Facebook — eventually tightened its rules on sharing and required users to give their permission before they can be added to groups.

And yet, fake news remains a central feature in a bitter election campaign, and WhatsApp continues to play a leading and powerful role in disseminating it.

All of it makes for real concern that the election will be tainted by fake news.

'Disservice to democracy'

"It's really hard to quantify," says Jaskirat Bawa, senior news editor at The Quint, a digital news website. But he says there are likely a lot of people that formed their opinion on how to vote based on fake information.

"Even if one person is voting based on fake information, we think it's a disservice to democracy."

Jaskirat Bawa works at The Quint, where the fight against fake news is a core part of what the team does on a daily basis. (Stephanie Jenzer/CBC)

The potential fallout from fake news is a sharpening concern in many parts of the world where elections loom — including the European Union and Canada. India's handling of the challenge during its multi-phase election, the largest democratic exercise in the world, could hold some lessons for the rest.

In the wake of the 2016 U.S. election, and eyeing India's vote down the road, The Quint started a fact-checking unit to monitor both the words of politicians and the content on social media for misinformation to debunk. The Quint says the pieces it has produced around this issue over the past two years are among its best-read stories.

Many newsrooms have since done the same.

"We've seen some mainstream media organizations go from, 'This is fake, so we're not going to touch it' to, 'This is fake, which is why we're going to touch it,'" says Bawa.

Watch as members of the team talk about fact-checking:

A digital news team says readers are keenly interested in stories that check the facts 0:40

But even as the fact-checking industry flourishes, so does the torrent of misinformation passed on by partisan cyber troops and ordinary users alike.

WhatsApp's restrictions, which limit forwarding messages to just five people at a time, appear to have been circumvented. Reuters reported this week that the limit can apparently be offset by a software workaround that costs as little as $14 US, allowing users to send thousands of messages at a time.

Watch as non-journalists get training on how to spot fake news:

Program aims to train 100,000 people in a country of 1.3 billion 0:32

The lure of reaching people directly on their cellphones, on a private, encrypted platform with between 200 and 300 million active users, has made WhatsApp indispensable as a political campaign tool. That for many people WhatsApp is also the primary source of news, outstripping traditional media, is also hard for political parties to ignore.

As a result, this is being called India's "WhatsApp election."

WhatsApp has more than 200 million users in India. (Stephanie Jenzer/CBC)

Cheaper, faster — and less expensive

WhatsApp has become "the primary means of political campaigning in the country," says Nikhil Pahwa, a journalist, digital rights activist and founder of MediaNama, which covers digital policy.

"It's cheaper, it's faster, it's better, it's less expensive to actually build a whole campaign around," Pahwa says, adding that it's also the "biggest source of misinformation in the country."

There is no end of examples:

In one case, a doctored photo showed Congress Party leader Rahul Gandhi walking with the suicide bomber behind the killing of 40 Indian soldiers in Kashmir in February.

Another hoax photo showed U.S. president Donald Trump apparently endorsing Prime Minister Narendra Modi.

A digital pamphlet made sexist and offensive allegations against a female candidate for the Aam Aadmi Party, and wrongly labelled her a "beef eater" and a non-Hindu.

Multiple reports based on accounts by former volunteers describe a relentless effort to discredit opponents online by any means — including well-staffed, sometimes paid cyberarmies recruited to help run campaigns.

'Battle is still on'

So-called IT cells are now a crucial part of any serious political war room.

Their primary aim is to promote party ideology, says Spandan Srivastava, who helps run the digital group for the Aam Aadmi Party. Secondly, he says: "We try to debunk fake news.

"So yeah, the battle is still on."

Spandan Srivastava, right, who helps run the digital group for the Aam Aadmi Party, says political parties use tech tools like WhatsApp to get their message out. But he says the parties are also involved in the fight against fake news. (Stephanie Jenzer/CBC)

A study by the University of Oxford revealed this week that ahead of the vote, more than a quarter of news links shared on Facebook pages supportive of Modi's ruling BJP party "were classed as junk news and information."

More than a third of images shared in BJP WhatsApp groups were "classed as divisive and conspiratorial." For the Congress Party, the figures were 21 per cent and 28.5 per cent respectively. Requests for interviews to both parties remained unanswered.

Some of this material is passed on not only from partisans, but from the main parties as well.

Malavika Balasubramanian is leader of the WebQoof fact-checking team, an arm of The Quint, a digital news platform. (Stephanie Jenzer/CBC)

"So effectively right now we're in a race to the bottom," says Pahwa. The resulting polarization, he added, will be felt for years.

But others believe the best way to mitigate the effects of fake news is to use the approach that makes WhatsApp so effective — getting trusted family and friends to pass information on.

That means taking the message of caution directly into the smallest alleys.

Adarsh Srivastava, 27, a community volunteer, has trained dozens of his own neighbours in the Kapashera community southwest of New Delhi on the perils of fake news.

"It has a huge impact on society… on our daily lives, social lives," he says. "It can impact… electing a prime minister."

Every year, some 50 million people get online in India for the first time, and often their first experience with the internet is through a cellphone — often one that arrives pre-loaded with WhatsApp. With messages reaching users mostly through trusted family and friends, people tend to forward messages without checking their veracity.

In the basement community centre Srivastava runs that's normally used for dance classes, workshops funded by WhatsApp help residents learn how to spot fake news and how best to pass the warning on to others in their circle.

Shivangi Gargi, a 17-year-old dance student who enrolled in the workshop, says she now alerts her friends and family to fake news: like the message she recently received claiming the Congress Party had won the election, even as the vote continues.

The focus of the training is on critical thinking and verifying messages before passing them on.

"Fake news and misinformation is more a social-behavioural problem than a technological problem," says Ravi Guria of the Digital Empowerment Foundation, which designed the courses that are now funded by WhatsApp.

"It's not something that could be addressed overnight."

Their modest aim is to train 100,000 — in a country of 1.3 billion people. The faint hope is that their message goes viral too.