The Internet Watch Foundation (IWF) confirmed 68,000 cases of self-generated child sexual abuse imagery in 2020 – 44% of the total cases it acted on last year and a 77% rise from 2019.
In 80% of these cases, the victims were 11 to 13-year-old girls, according to new analysis in the IWF’s annual report.
And 17% (11,261 cases) were deemed to contain Category A material – the most severe level of abuse.
Siblings as young as three are being encouraged to take part together, with the IWF seeing eight images or videos on average per working day between September 28 and December 23.
Self-generated content can include material filmed using webcams, very often in the child’s own room, and then shared online.
In some cases, children are groomed, deceived or extorted into producing and sharing a sexual image or video of themselves.
IWF analysists have seen videos of children mouthing words as they read comments or probable instructions, and children being shown sexual material online and being asked to copy it.
The internet watchdog has launched two campaigns, which have received funding from the Home Office and Microsoft, to help girls and their parents become more aware of the risks.
In a shocking video aimed at parents, men can be seen queuing up outside a family home, entering through the open door and surrounding a teenage girl in her bedroom, as her mother shouts up that dinner is ready.
The Home Truths campaign video then says: “Make sure your home doesn’t have an open door to child sexual abusers.”
Susie Hargreaves, IWF chief executive, said predators are finding new ways to manipulate children who are, in many cases, “a captive audience at home with their devices”.
She continued: “Some of the campaign is shocking. But the threat and the abuse is shocking.
“We don’t want to frighten people, but we do want to build resilience to the threat of self-generated sexual abuse of children.
“We want to help teenage girls to recognise the actions that constitute self-generated sexual abuse as abuse.
“We want them to feel empowered to take control, and to understand how to deal with inappropriate requests and report them to a trusted source.”
The “Gurls Out Loud” campaign will target teenage girls through social channels including Instagram, Snapchat, TikTok, YouTube and Google display.
Tink Palmer, chief executive of the Marie Collins Foundation, a charity which works to help victims of child sexual abuse and their families, said in many cases it is pre-pubescent children being targeted.
She said: “They are less accomplished in their social, emotional and psychological development.
“They listen to grown ups without questioning them, whereas teenagers are more likely to push back against what an adult tells them.”
Ms Hargreaves acknowledged the term “self-generated” is problematic but said it must be “couched in understanding that we’re talking about very little children here, and that actually, even if they have seemingly willingly engaged in that process, they are actually being tricked and manipulated by forces they have no control over.”
Parents are encouraged to talk to their child about the risks, agree ground rules, learn about the platforms their child uses and know how to use tools, apps and settings to keep their child safe online.
In November, the All-Party Parliamentary Group on Social Media launched an inquiry into the “disturbing” rise of self-generated child sexual abuse material.
The Home Office has called the rise “deeply concerning”.
Home Secretary Priti Patel said: “The scale and severity of online child sexual abuse is shocking, and highlights the importance of our proposed Online Safety legislation requiring technology companies to keep their users safe online, particularly children.
“But these companies should not wait for legislation to be in place before they take action to address these abhorrent crimes.”