It is a legal precedent in Britain that should indicate that the Terrorism Act has no age limitations:
“The youngest person in Britain to have been convicted under the Terrorism Act has been sentenced to two years in a young offenders’ institution.
Hammaad Munshi, from Dewsbury, West Yorkshire, was 16 when he was arrested in 2006. Police found a guide to making napalm on his computer.”
The choices that Hammaad Munshi made as a teenager will follow him through the rest of his adult life. It is regrettable judgement for a sixteen year old. However, it does show that the judiciary will enforce the Terrorism Act in earnest.