"They take the western media and they blame them a lot and it makes them turn away from Australia and Australian culture. That's one of the biggest reasons why people go over there," said Abu Zaid, a committee member at the Hume Islamic Youth Centre, where Mr Bilardi sometimes went to hear lectures. Fairfax Media revealed on Sunday that the young westerner pictured last December sitting between bearded men and holding an assault rifle in front of the black flag used by IS was actually an 18-year-old Australian. According to Jake's aunt Connie, he became more vulnerable after his mother died in 2012. Abu Zaid said media portrayals of radical Islam "sparks the curiosity and that spark is all it takes to develop someone's idea about something". "That idea could be positive, 'Oh look, everyone speaks against them, maybe there's some truth there that they are trying to hide ... so they go and do their research and they develop their own theories." The people who developed more radical mindsets "stick to themselves and a lot of the time, their mindset comes out completely wrong from the reality".

"He is a person, he sticks to himself, stays in his room. Believe me, if you just give him a laptop in the room, he'll stay there all day." Abu Zaid said he saw no problem for Australia if someone went to another country to fight. "Isn't all Australian culture about freedom of choice, freedom of speech, freedom of all this? Why is it OK, for example, for the Jews to recruit kids from here to go and fight in Israel and no one make any fuss about that, but then one person under the name of Muslim - maybe he's Muslim, maybe he's not Muslim - to go and fight overseas in what he believes in, even if it's wrong? ... a person has an idea in his mind, he believes it's right, he should fight for what he believes in." He believed that going to fight in Syria was "not such a big issue". "A kid, he was lusting to go, he thought it was right. He has an idea in his head, he wants to fulfil the idea. Forget about wrong or right. He's gone. What's that got to do with Australia? He wants to leave, OK, he's not harming anyone in Australia, he's not a terror threat to Australia ... Who cares. That doesn't concern us".

However, Australian Islamic Mission's Dr Seyed Sheriffdeen said the Islamic community in Melbourne was desperate to learn more about how IS was recruiting from western countries to help stop it. "My community is not in favour of converting somebody and fooling them into picking up a gun," he said. "We really do not know how they attract western kids to go there. It looks like the hot spot for their recruitment is the western world and we do not know how, we don't know their method of recruitment." Mr Bilardi was described as "a quiet boy" and there was shock from those who knew him that he had left to fight for IS. "I've actually never seen him utter a word at the table when I was serving the food, cleaning up the table, nothing," said Furkan Derya, who used to work at the Hume Islamic Youth Centre.

"He was the last person I would expect to actually go there." Another former classmate, Jamie Kassan, said he "didn't really seem happy" before he converted to Islam. "Afterwards though, he seemed more joyful. He was always extremely smart, quite timid and that didnt really change after he converted, although he spoke more freely about his religion." Ulus Shefket, who went to school with Mr Bilardi in Craigieburn, said he was "a shy kid who didn't like to be disturbed". "I'm speechless," he said. "Who would've thought someone like him would join a terrorist organisation. I can't even imagine what his family is going through right now."