A peaceful protester received racial abuse and threats online - all because of a case of mistaken identity.
The first message was confusing. It came from a journalist via Instagram, asking Momo whether he was the person captured on video atop a war memorial, seemingly trying to burn a union jack.
He had no idea what it was all about, so at first he ignored the message. But soon a friend sent him a Facebook post. It featured Momo's photo. Threats and abuse dominated the comments.
"He should be hanged, drawn and quartered!"
"Go back to your country!"
Others were much, much worse. It dawned on him that he had become the target of a campaign accusing him of torching the national flag at the Cenotaph, the memorial to Britain's war dead on Whitehall in central London.
It was a case of mistaken identity - obvious to anyone who bothered to make even the most cursory check. For one thing, photos and news reports identified the person who climbed on to the Cenotaph not as a man, but as a woman.
But a few influential accounts published Momo's real name - we agreed to call him by a pseudonym because of the risk of further abuse - and soon his picture was going viral for the wrong reasons.
The 23-year-old Londoner is a recent graduate, working as a tutor and looking to set up a sustainable fashion brand. He spoke exclusively to BBC News about what happened to him.
The death of George Floyd moved him to action - he wanted to highlight the roots of racism beyond the US, in the UK as well.
And so on Wednesday 3 June, he joined peaceful anti-racism protests in London. He donned a red, white and blue anorak and headed out into the drizzle with a few friends, carrying a sign that read: "The UK invented racism".
They marched and chanted, and a few hours later, wet and shivering, Momo returned home.
He deliberated for a few days about posting the photo of himself at the protests on his social media accounts, but eventually did on the following Monday, 8 June.
Unbeknownst to him, something significant had happened in between. On Sunday 7 June, further protests were held in central London.
Although large and mostly peaceful, they were marred in the evening by a smaller, violent group. Twelve arrests were made and eight officers were injured, police said, following similar scenes the day before.
The Cenotaph flag incident happened in the middle of the melee. Pictures and news reports clearly show a person atop the monument's plinth. Like Momo three days before, she was wearing a red, white and blue anorak.
That's where the similarity ends, however. Momo bears little resemblance to the woman pictured at the monument. They have different face shapes and builds, and if you look closely, the pattern on their anoraks is clearly different.
But apparently fuelling the online mob is one thing they do have in common: they are both black.
"It's become clear to me that this isn't about naming and shaming the person who set fire to the flag," Momo says. "Instead it's about targeting a black person with abuse."
The Metropolitan Police say a 20-year-old woman was arrested on suspicion of criminal damage in connection with the incident at the Cenotaph. She has been bailed to a later date in July.
Momo didn't panic until his brother noticed one particular viral tweet. Momo's picture was shared by a Twitter account, @nathansbritain, which recently has been devoted to messages opposing the Black Lives Matter protesters and supporting US President Donald Trump.
"This is the scumbag who thought it was a good idea to set the Union Jack on fire on Whitehall," @nathansbritain wrote. "I hope he is proud of himself, the filthy rat."
Although the account wasn't huge, thousands of people retweeted and commented. The replies were littered with racist abuse.
In a statement, Twitter told BBC News: "Users cannot promote violence against, threaten or harass other people on the basis of race, ethnicity or other protected groups." But the company also said that the tweet from @nathansbritain is not in violation of its rules.
The person behind @nathansbritain did not respond to attempts to contact them for comment.
From Twitter, Momo's picture was shared in other places, including on Facebook and Reddit. In one group, the poster declared: "Let's make this scumbag famous". That post racked up 1,500 shares and hundreds of comments before Facebook removed it along with another one repeating the false claim.
A Facebook spokesperson said: "We don't tolerate abuse, bullying or harassment on our platforms and we encourage those affected by this behaviour to report it so we can take swift action."
Despite dozens of people pointing out the clear case of mistaken identity, many other accounts sharing Momo's picture have not corrected their posts or taken them down.
'I didn't expect it to be like this'
The abuse continues, but Momo says he's not removing his original photo - the one of him at a peaceful protest - from his social media accounts. He's asked family and friends to report posts containing the false claim, and says he's not surprised by the abuse.
"So many friends messaged me saying, 'Can you believe this is happening?' Trust me, I can believe it," he says. "As a black person, I'm so used to hearing and seeing these kinds of comments.
"This whole situation really highlights the dehumanisation of black people online. People just see a picture, people just see a face. People don't see a human with a family.
"It shows the importance of fact-checking - and the Black Lives Matter movement."
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