According to reports, not less than eight men have taken their own lives after being ‘unmasked’ by online “paedophile hunters”.
In most cases, they killed themselves within days of being filmed and named and shamed.
Research by the BBC’s Victoria Derbyshire programme has uncovered the eight fatalities, which are thought to be linked to their public shaming.
Paedophile hunters say they are keeping the public safe, but family members of those who died say they are forced to pick up the pieces.
One woman whose father killed himself believes such groups are hindering justice.
Lesley, whose father Michael Duff was snared in 2015, says she now lives with unanswered questions and faces vile rape threats against her.
Speaking to the show, she said: “I loved him to bits. He was a born entertainer.”
Lesley had always adored her father and never suspected he might have another side.
But in July 2015, while at home with her daughter, she was told about a video of him being confronted by a paedophile hunter, that had begun circulating widely on social media.
The 15-year-old boy her father thought he had been contacting was actually someone using fake profiles to try and attract and expose potential child sex offenders.
“My friend said, ‘Look, I don’t really know how to say this to you Lesley, but there’s a video going round on Facebook – it’s your dad’.
“I just sort of sat in shock,” she said. “It was on Facebook and I could already see what mutual friends had viewed it, so there was nothing I could do.
“I must have been screaming because my daughter was upstairs… she could hear me screaming, and she asked me what was wrong.”
She told her daughter, then also aged 15: “Your granddad’s a paedophile”.
After showing the schoolgirl the video – something she now regrets – neither of them ever spoke to Duff again.
He handed himself into police that day and had his computers confiscated. He was released after questioning, and two days later killed himself.
She has decided to talk so that “paedophile hunters” can understand the wider ramifications of their actions.
Lesley says, in many ways, it has become nothing more than “parading” individuals for others to judge.
“I didn’t want to ever tell my story,” she says, “because I didn’t want to bring it all back on myself.
“[But] it’s getting to a point now where people do need to know that when they’ve posted that video on Facebook, while that’s where it ends for them, that’s not where it ends for us [the families].”
But “paedophile hunters” have defended their actions.
Jamie Lee, 29, who describes himself as a “child protection enforcer” said he is performing a public service.
In the show, he shares a video of one of his stings, on a middle-aged man named Robert who thought he had been speaking to a 14-year-old boy online. In fact, he had been talking to Jamie.
“Robert approached me,” said Jamie, who says he always waits for men to contact the children first, “and after around two weeks he got quite graphic, telling me all sorts of vile stuff he was going to do to me.”
In the video, Jamie confronts the man as he gets out of his car, asking him to hand over his keys so he knows he will not flee.
“If you find young boys in school uniform attractive what are you?,” he asks, to no reply.
“Do you like young boys?,” he tries again.
“Yes, but I’ve never been with one of them,” the man replies.
The video was being streamed live on Facebook, with the man identified.
“You see his face change,” Jamie remarks, watching the video back. “The colour drains from his face. He knows that he’s in trouble.
“It’s slowly sinking in that this good life he’s got is about to come to an end. He admitted everything once he realised that he’d been caught red-handed.”
Robert went to prison for a few months after the sting – he pleaded guilty to attempting to engage in sexual communication with a child. He killed himself when he got out.
Jamie says he “never expected” that to happen.
“My goal is for these men to face what [they’ve] done. I was devastated when I found out Robert had killed himself, more so for his family.
“I’m still telling myself it’s not my fault – I just feel slightly guilty that a man has lost his life because of the way I approached it.”
On some occasions, police do work with so-called paedophile hunters.
But the National Police Chiefs’ Council (NPCC) says such individuals can undermine police investigations with poor evidence. They are also worried about vigilante retaliation and suicides.