The 'ninjas' fighting climate change denial on Twitter

Secretive internet vigilantes have made it their mission to fight climate change denial on Twitter. But, as a vicious information war rages online, do they risk becoming the very trolls they claim to be targeting?

I meet Maria and Arthur at the top of a hill overlooking the Mediterranean Sea, in a small coastal town in Spain.

They ask me not to reveal their real names or their exact whereabouts. Over the years, they have made countless enemies on the internet, and they believe stepping out of the shadows could prove dangerous.

"For you to be able to do your work, and not be scared of the consequences, you really have to fly under the radar," Maria tells me.

In 2019, she helped set up Team Ninja Trollhunters, a group of 25 people from around the world who came together to fight climate change denial on Twitter.

"For me, it was a necessity to show that many things that are being tweeted are wrong," Maria says.

Like some of her fellow vigilantes, she has a background in science, which comes in handy when looking through complex research.

But, with her blue Snoopy t-shirt, Maria does not immediately strike me as a "ninja" - and neither does her softly spoken partner, Arthur, whom she recruited into the group.

"We fought many battles together and we also had a lot of fun," he says.

When the group first came together in 2019, part of its time was spent fact-checking false or misleading claims they found on Twitter.

The "ninjas" spotted claims going viral and responded to them with links to factual information - academic papers or scientific reports.

"But after a couple of months, you realise you don't make an impact because, for most of these people, facts are irrelevant," Maria says.

It was time to come up with new tactics.

The "ninjas" began keeping tabs on prominent Twitter accounts which disputed the basic science of climate change. Whenever those users tweeted something which broke the platform's rules, they would report them.

Climate change denial is not forbidden on Twitter, but some other types of content are - like threats, harassment, or hate speech. Until November last year, posting misleading claims about Covid-19 could also lead to tweets being removed or accounts being suspended.

"At the end of the day, it doesn't matter whether they get suspended because of Covid-19 misinformation or Nazi symbols," Maria tells me. "When they're gone, they're gone."

You can listen to "Twitter 'ninjas' against climate denial" on BBC Sounds.

Thousands of hours of slow, painstaking work paid off - or so the "ninjas" like to believe. They claim that, as a result of their actions, about 600 Twitter accounts promoting climate change denial were suspended.

I cannot independently verify this claim. But I have seen links to hundreds of offending tweets that the "ninjas" reported , as well as a detailed list of suspended accounts.

One of those accounts was Mike's. He is an Australian engineer with more than 23,000 followers on Twitter - many of whom believe in conspiracy theories.

In April last year, his account was permanently suspended from Twitter, after posting an unfounded claim about Covid vaccines.

Up until that point, the "ninjas" had been keeping watch on his feed, reporting dozens of his tweets. In a private forum, they added Mike's handle to their list of claimed scalps.

"I'm not surprised in the slightest," Mike says. Over the years, he claims to have been repeatedly targeted by groups like this one, which he accuses of "trolling" users like him.

The "ninjas" share a set of rules laid out in a document called "The Resistor's Guide to Effective Trollhunting". In it, members are advised "not to engage" with their targets. And yet, by their own admission, each member of the group has their own way of operating.

Maria insists she always played by the rules and that she "knew where the line was". But Arthur's methods led to him getting temporarily suspended from Twitter "a couple of times".

"When I engaged climate change deniers, I noticed some of them got agitated. So I continued to do it, until the point they showed harassing behaviour [against me], which is not allowed," he told me. "Then you can get rid of them."

I suggest to Arthur that his behaviour may not be dissimilar to that of an online troll. "You could say that, because it is partially true," he replies.

But I point out to him that, by provoking his targets into crossing a line, he could be causing real-world harm.

"I can't see any real-world damage worse than what they are doing," he says. "When they are trying to convince people climate change is a myth, they are inflicting damage upon all of us."

But the "ninjas"' efforts have been somewhat hampered by Elon Musk's takeover of Twitter. Last November, the billionaire announced the platform would reinstate thousands of previously suspended accounts.

Mike's account was among them.

"That was a slap in the face," Maria says. "If Twitter decided that these people should be suspended, there was a good reason for it."

Twitter did not respond to requests for comment.

Maria and Arthur have now left Twitter, but other members of the group have stayed there. Their online battle continues.

I have spoken to several of the group's current members, and they described a recent "uptick" in climate misinformation circulating on Twitter.

For Arthur, this proves just how relevant the "ninjas" continue to be. "If just a fraction of regular people would do what we did, we would be much louder than all deniers together."

You can listen to Twitter 'ninjas' against climate denial on BBC Sounds.