Half of all British jihadists are now radicalised online to plot terror, an alarming study has found.
The proportion of vulnerable young Muslims brainwashed by groups such as Islamic State over the internet has doubled in the five years to 2015.
Some 53 per cent of the UK’s Islamist terrorists were inspired by extremist material on the web in that period, compared to just 22 per cent before that.
The figures illustrate that Islamist fanatics are using Hollywood-style propaganda films to spout hatred, extremism and murder to encourage individuals to carry out attacks on the streets of Britain.
The statistics also raise questions about whether internet giants are doing enough to tackle the threat.
Google, Facebook and Twitter have been blasted for deliberately failing to stop jihadists using their sites to promote terrorism and killings on UK streets.
The latest findings were contained in the most comprehensive study of terror convictions in Britain.
The 1,000-page report from the Henry Jackson Society covers all Islamist convictions and suicide bombings from the first in 1998 to the beginning of last year.
Report author Hannah Stuart, senior research fellow at the security think-tank, said: ‘Online radicalisation is increasing – the prevalence of the internet as a medium for engagement with extremism more than doubled.
‘First Al Qaeda and now Islamic State are ahead of the game in terms of using the internet and social media for propaganda.
Islamic State is now increasingly using the power of the internet to target people. It is now much easier to find extremist material.’
In August last year, MPs on the Commons’ Home Affairs Select Committee said forums, message boards and social media platforms were the ‘lifeblood’ of Islamic State and other terror groups.
Extremists used networks such as Google, YouTube and Facebook as the ’vehicle of choice in spreading propaganda’ to recruit terrorists – yet the companies did too little to tackle those glorifying violence, they said.
The scale of the problem was drummed home when it was revealed that social media firms had refused to remove hate preacher Anjem Choudary’s poisonous online rants that urged Britons to carry out atrocities before he was jailed.
Meanwhile, the Henry Jackson Society report, published yesterday TUES, also found that two-thirds of terrorists convicted in UK courts were previously unknown to MI5
Those who had been identified by the security services had halved from 61 per cent before 2011 to 29 per cent afterwards.
This suggested a growing challenge for spies because a growing proportion were so-called ‘clean skins’.
Only 10 per cent of terror attacks were carried out by ‘lone wolves’ unconnected to wider extremist networks. And 1 in 10 terrorists had watched a beheading video – pushing them to even greater depravity.
The report said the increase in plots involving knives makes tackling the problem harder for the security services than when terror cells plotted bomb strikes.
Miss Stuart said: ‘The security services could watch groups until they had enough evidence to make a case in court.
That is harder now with knife attacks, compared with when groups were spending months acquiring bomb-making equipment. That is a big difference.’