Paedophiles may soon be able to hide behind a cloak of encryption when they prey on children over the internet.
That's the grim warning from police, as the Norfolk man dubbed one of Britain's most prolific online sex offenders was jailed for 25 years after admitting a vile catalogue of abuse on children as young as four.
Roofer David Wilson, 36, from Kirstead, King's Lynn, entered guilty pleas to 96 offences against 51 victims.
He posed as teenage girls on Facebook, grooming boys to send him indecent images, blackmailing some into performing increasingly obscene acts or abusing their siblings.
Prolific paedophile from King's Lynn jailed for 25 years (Warning: Some viewers may find this video distressing)
Officers from the National Crime Agency moved in after being tipped off by the social media giant.
It told them a number of boys had been sending indecent images of themselves to an account purporting to be a 13-year-old girl. The fake account and others like it were eventually linked to Wilson.
But police fear changes to its app which will offer end-to-end encryption of messages mean Facebook may not be able to detect those who use it to abuse children in future.
Home Secretary Priti Patel said: “The tireless efforts of the NCA have put a truly awful criminal behind bars, providing justice to those who suffered as well as protecting hundreds of potential victims.
“This sickening case is a chilling reminder of how crucial it is that tech companies play their part in combating child sexual abuse.
“It is vital that Facebook do not press ahead without amending their current end-to-end-encryption plans, otherwise sick criminals like David Wilson could still be abusing children with impunity.”
Rob Jones, the NCA's director of threat leadership, said: "It's the biggest single issue that's going to affect our ability to tackle child abuse online."
Mr Jones said in 2020, 4,500 people were arrested on suspicion of online abuse and 6,000 children were safeguarded after police received referrals from social media platforms which had detected obscene images.
More than 50pc came from Facebook. But encryption will mean fewer referrals, because social media platforms will not be able to see what material users are exchanging.
"Over the next few months, the privacy model they are creating effectively locks them out of their own network," said Mr Jones. "It creates a private place, where people like Wilson can masquerade as children.
“Facebook’s plans are a disaster for child safety and law enforcement and mean the very many other David Wilsons out there will not be caught.
“Criminals will be drawn to Facebook, emboldened and confident it’s a place they can search for children to sexually abuse with complete impunity."
Mr Jones said the change posed "a real threat" to the safety of children on social media platforms, which offenders used to target victims.
He added: “In 2019 Facebook made 15.8m global referrals of child sexual abuse material, they have been a huge help to lawful investigations and child safeguarding.
“But their plans will create a haven for child sex offenders to congregate to target children. It’s not too late for Facebook to change their mind.”
Simon Bailey, Norfolk's Chief Constable, is the National Police Chief's Council's lead for child protection.
He said: "Facebook are responsible for the vast majority of referrals around child sexual abuse materials and the Facebook platform is used to share and distribute wholesale child sexual abuse material.
"Facebook know this and whilst they would argue they are doing everything they can, as demonstrated by the number of referrals to the National Center for Missing and Exploited Children, the fact is they still permit those images to be uploaded and shared, when the technology exists to prevent that.
"They know they have this huge problem and their answer is to put end-to-end encryption in so they can't see it.
"We all want and expect privacy to be applied for legitimate transactions and activity, but it cannot be right that paedophiles can expect their activity to be protected too."
Mr Bailey said he had raised the issue of encryption at "the very highest levels of government" and at national and international conferences.
He added: "In my opinion Facebook are washing their hand of their responsibility to protect children and to identify those who would seek to exploit children and young people.
“The information from Facebook was crucial in bringing Wilson to justice. Which is why I am concerned about Facebook planning to introduce further encryption and privacy protections, making it harder for us to prevent exploitation and find child sexual abusers like Wilson."
In a statement, Facebook said: "“Child exploitation and grooming have no place on our platforms.
"Facebook has led the industry in developing new ways to prevent, detect, and respond to abuse and we will continue to work with law enforcement to combat criminal activity.
"End-to-end encryption is already the leading technology used by many services to keep people safe and we will build on our strong anti-abuse capabilities at WhatsApp when we roll it out on our other messaging services.
"For example, through a combination of advanced technology and user reports, WhatsApp bans around 250,000 accounts each month suspected of sharing child exploitative imagery.”
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