Isis extremists are using Instagram to promote jihad and incite support for terror attacks on the West, an investigation by the Sunday Telegraph has found.
They are circumventing the platform's security checks to post images and text celebrating the killings of "kafir" (unbelievers) accompanied by images of dead soldiers and beheadings, as well as threatening terrorist atrocities on the scale of the Sri Lankan suicide bombings that claimed 253 lives.
Some posts brazenly use Isis' logo or images of Abu Bakr al-Baghdadi, the group's self-proclaimed leader, and urge followers to join jihad.
The investigation exposes serious flaws in the ability of social media giants to prevent extremists exploiting them to promote their causes.
It also found that live-streamed footage of the attack on mosques in Christchurch was still up on Facebook's site two months after the atrocity in which 51 people, including children, were fatally shot.
After being alerted to the posts by the Telegraph, Instagram and Facebook removed the accounts and video, insisting they would not tolerate terrorism on their sites.
However, Ben Wallace, Britain's security minister, said the investigation showed the firms were failing to do enough to block extremism that could radicalise others. "It's vital tech companies do more to ensure their platforms are not used for these purposes," he said.
Yvette Cooper, chair of the home affairs select committee, said the discovery was "an utter disgrace".
"We have challenged the companies many times on the way their money-making algorithms are promoting extremism — these companies are profting from pushing poison," she said.
The posts were uncovered by Eric Feinberg, of the Global Intellectual Property Enforcement Centre, who has developed technology that can detect communications and euphemisms of terrorists in Arabic and other languages and thus trace material missed by the platforms.
He is now being followed by Isis supporters and, in a twist, Instagram's algorithms have started recommending to him Isis sympathisers to follow.
Feinberg said: "This material is designed to incite, radicalise and recruit Isis sympathisers and lone wolves. All it takes is one person to be inspired by this and people could die as a result."
The investigation uncovered dozens of accounts daily on Instagram carrying images, videos and speeches.
One headlined "Choosing the next target, no method is off limits" points to previous attacks, with a red question mark over: "Who is the next ... "
Two dead PKK soldiers on the Turkish-Syrian border were accompanied by script praising the killing of "two kafirs" by "soldiers of the caliphate".
Some of the most shocking images showed an under 1-year-old in a baby walker below Isis iconography and a child in combat fatigues preparing to behead a prisoner. Instagram said it worked "aggressively to remove content or an account as soon as we become aware of it".
Facebook said the way the Christchurch video had been edited from the live-streamed version had prevented it from being detected until now.
"There's no place for this type of content on our platforms," it said.
Feinberg, however, claims his evidence shows such statements are hollow. Over 60 days in December and January, he identified 900 separate Isis accounts on Facebook — 15 a day, which he presented to the company. It is understood all were removed.
He said he had offered his technology to the platforms but they had rejected it.