FTA:

The so-called "Five Eyes" intelligence-sharing network that usually shuns the limelight, comprising U.S., U.K., Canadian, Australian and New Zealand security agencies, is so alarmed that it took the unusual step in December of calling publicly for collective action, saying: "Radicalized minors can pose the same credible terrorist threat as adults."

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For some kids, the process starts with violent pornography or a fascination for gory images, counterterrorism investigators say. From there, more clicks can lead to grisly murder videos from Mexican drug cartels and ultimately to jihadi decapitations, throat-slitting and torture, in videos that are sometimes slickly produced with music and are shared on chat groups.

"Often they're heavy consumers of everything that is broadcast on the Web and especially things that are forbidden," said Christen, the French national anti-terror prosecutor. "It's something of a chain reaction that gets them to the ultra-violence disseminated by jihadi movements."