The first thing 16-year-old Kiaira Manuel did when she saw a bold, underlined sign reading “COLORS ONLY” over one of her high school’s hallway water fountains was go to her school administrators.

“They said they were going to handle it, but so many things go unnoticed at this school and they just don’t care,” says the now 17-year-old, explaining her decision to post a picture of the sign on social media that night. “So this was taped above the water fountains at my school...” she innocuously captioned the image, which has now been shared over 1,500 times.

So this was taped above the water fountains at my school... pic.twitter.com/K5yQCe7vsX — Κιάιrα ♡ (@BlvckConscious) January 25, 2016

It took a day for someone to call her a liar. Twitter user @iH8Thots tweeted Manuel a message, which was then also shared hundreds of times on the site. “We go to the same school,” he wrote. “I watched you put that piece of paper up there and take the picture.” Manuel blocked the user, which was then seen as “proof” that his accusation was true.

These tweets were first posted in January – when the sign was stuck over the water fountain – but over the last few days, Manuel has fended off a fresh flood of people taking to social media to call her a liar. The timing is no accident. Since Donald Trump won the United States presidential election, there has reportedly been an increase in hate crime in America – with the Southern Poverty Law Center receiving 200 complaints in the last week. There has also, in turn, been a surge in people trying to discredit hate crimes, by loudly labelling them hoaxes on social media.

It doesn’t take a lot of research to unravel @iH8Thots’ claims. Less than a week after the incident, he and Manuel appeared on the comedy podcast Pod Awful to talk about their viral tweets. “You’re clearly a fucking troll,” says the host within a few minutes of speaking to @iH8Thots, even though he initially believed his story. @iH8Thots refuses to explain his side of events, is unsure of his own age, and calls his lawyer – who has, in the host’s words, “the voice of a child” – to defend him on air. When I asked – over Twitter’s direct messaging service – whether @iH8Thots would like to speak to me for this piece, he replied: “lol. fuck the media. journalists can go to hell”.

Before all of this, however, a cursory glance at the profile of @iH8Thots – a username that, translated from internet slang, seems to mean “I hate That Hoe Over There” – was enough to disprove his accusations. Manuel claims that when he first posted the tweet, his account said he was based in California, nearly 3,000 miles from her high school in Florida. His feed was full of similar trolling messages, and if you click on his account today, you will see a man in a gas mask holding a gun staring out from his profile picture, a design for a fascist flag of America as his header, and a timeline full of pro-Trump and anti-liberal tweets. Few people, however – both when the tweet first blew up and now it has reappeared – think to check.

Manuel’s experiences are part of a current trend on social media that I will tentatively call a “hoax hoax”. It goes like this. Someone posts evidence of a hate crime on social media. Someone else uses false evidence to out their post as a hoax. This, however, is the actual hoax. It is a lie claiming someone else lied – a hoax hoax.

This is happening on fake news websites and across social media. A Twitter account @DidntHappenUk was set up last month to expose people they believe to be lying on the social network. Despite offering no evidence for who is or isn’t telling the truth in any scenario, they have over 2,000 followers – with half of these gained over the last week since the election. “A nice display of left hand writing here,” they wrote above a picture of a swastika-laden racist message that was allegedly left on a Facebook user’s car.

So what do we reckon on this one then?actions speaks volumes, feel free to respond @BlvckConscious. Prepare to start blocking a lot more imo pic.twitter.com/5Te8kE9C5O — It didn't happen... (@DidntHappenUk) November 13, 2016

“People think that, after the election, people are making up hoaxes to prove that there is hate in the world. It’s so stupid. People don’t do their research on these things and now I’m being used as a prime example for it,” Manuel says.

The problem is being exacerbated by police forces using social media to encourage victims to come forward. Twitter users jumped on the journalist Sarah Harvard when she claimed her friend’s Muslim sister had “a knife pulled on her” at her university and the campus police replied saying: “This has not been reported to police. If you are in contact with anyone involved, please encourage them to give us a call.” Though they meant well, their tweet was used as evidence that the event never happened at all. This is a problem because police reports are not the be-all and end-all of proving a claim’s veracity.

Manuel says her school administrators, for example, were reluctant to act when she reported the water fountain incident, and she felt they were dismissive of her concerns. “When I put it on social media it was forcing them to actually pay attention and actually do something about it,” she says. Contrary to what many might expect, then, some people – especially those who are disenfranchised – are compelled to turn to social media over the authorities.

“That’s why we put stuff as ‘Unproven’,” says Brooke Binkowski, the managing editor of the internet’s oldest fact-checking website, Snopes, which uses “True”, “False”, "Mixture", and "Unproven" buttons to label stories. They recently labelled a story about a Muslim woman told to hang herself with her hijab in Walmart as “Unproven” after the police said they had not heard about the attack.

“We didn’t want to say ‘False’ because there’s not much we can do if two people were involved and neither of them are talking and nobody saw it. Maybe she didn’t want to go to the police. All sorts of creepy people will start threatening people who do so. And the people who are doing it certainly aren’t going to say ‘We told her to hang herself by her hijab’.”

So, in other words, this never happened. pic.twitter.com/F5LgIpWJ3f — Ashley Rae (@Communism_Kills) November 10, 2016

Snopes are a non-partisan site, and investigate claims based on how many people email them to ask about a story. “Inherently, fact-checking hate crime accusations is certainly sticky,” says Kim LaCapria, a content manager and political fact-checker at Snopes, when I ask whether there are any moral considerations around investigating hate crimes. “There's definitely the idea out there it's wrong to question people who we agree with that have been purportedly attacked, but folks on the other side of the aisle clamour for a look into claims' veracity.”

It is important to note that there are undeniably hate crime hoaxes – something the right often calls “false flags” – occurring, though Binkowski says they are “extremely rare”. The conservative news website Breitbart – which has found fans among white supremacists – concludes that there have been 100 in the last ten years, a remarkably low rate of ten a year (especially considering the site’s agenda) and nothing compared to the 2,241 racially or religiously aggravated offences that occurred in the UK in the two weeks after the EU referendum. The right is also guilty of false flags, recently purporting a man was attacked because he was a Trump supporter when the incident actually stemmed from a traffic altercation.

Still, when false flag hate crimes do happen, they are seized by the right as evidence that no hate crimes are happening at all. Who can forget when, earlier this year, an openly gay pastor was forced to admit he had iced the word “Fag” onto a cake himself, and had lied that it was done by a Whole Foods employee? Just last week, a student at the University of Louisiana admitted to fabricating a story about having her hijab ripped off by two Trump supporters (it is worth noting, however, that some people may recant their stories out of fear).

It is crucial that we, as social media users, fact-check things before we share them so they can’t be used for another agenda. Just because fake hate crimes are rare doesn’t mean it’s wrong to scrutinise things you see on social media. Questioning one particular post that seems a little off is not the same as denying that hate crimes are happening.

“Even if it feels uncharitable to consider the veracity of a claim, it's important for information to be credible and not to add to the spread of bad information inside a political bubble of one's own making,” says LaCapria. “Liberals are most definitely not immune to spreading bad information or getting angry when their claims get debunked, but it doesn't help anyone's cause when a popular story inevitably proves false.”

It can be very distressing, however, for a victim to be accused of carrying out a hoax, and Manuel ended up blocking over 600 people on Twitter. “People started attacking me and calling me ‘n****r’ and all of these derogatory terms,” she says. “Two days ago, after this all blew back up, I got 50 messages in a row from one person who said he was watching me, and said my first name and last name and said my information had been leaked. That’s really frightening.”

Expose this HOAX please. Chris Bawl works in special effects, claims Trump supporter attacked him cause hes gay. https://t.co/lekOq6R7Ix pic.twitter.com/EKg4oODjZ3 — Sheeple (@sh33ple) November 11, 2016

While fact-checking, it is crucial to not cause unnecessary distress. But how?

“Even a simple ‘I haven’t verified this yet’ or ‘If this is true, it’s worth paying attention to’ marks the story as unvetted but allows people to share,” says LaCapria. “Critical thinking is important; if something sounds completely implausible, it probably didn't happen the way the person is telling social media it did. There are two good subreddits – r/thathappened and r/quityourbullshit – that just take a second (sometimes mocking) look at viral social media claims. Although users aren't always kind, they can be very good at pinpointing holes in stories.” Another, r/hatecrimehoaxes has also become popular after the election.

Binkowski also points out that many hoaxes fall apart at the first sign of scrutiny. “They usually make it easy because they can’t handle the pressure and feel guilty so come out and recant,” she says. “Everyone should read from a variety of sources, even ones you don’t agree with. A lot of people yell at us because they think we are trying to be the be-all and end-all but we just want to be the starting point."

For Manuel, everyone being better at fact-checking would have saved her a lot of pain. At the time of writing, her Twitter mentions are still being flooded with offensive messages. In order to combat both hoaxes and hoax hoaxes, then, everyone must attempt to be non-partisan in scrutinising social media claims.

"Even if you don’t have much time, if you read something on some site that doesn’t quite ring true or seems too perfect, then Google it, just Google it,” says Binkowski.