Canadian security agents knew about Farah Shirdon before he left his home and joined the ranks of foreigners fighting in Syria and Iraq.

They asked him questions, tried to discourage any travel. But less than a week later he was gone.

Relatives of Mohamud Mohamed Mohamud, of Hamilton, did not know he had left until it was too late. The 20-year-old was already in Turkey when he sent a text, saying he was bound for the border with Syria. They called the RCMP and tried to stop him, but it is believed Mohamud was killed this week, joining the list of foreign fighters to die after aligning with the Islamic State.

These cases — and potentially dozens of others involving Canadians and thousands abroad — have consumed Western governments and the media for weeks, as the fight in Syria and Iraq intensifies.

How are foreign fighters lured? What danger do they pose? How to balance the attention the issue deserves, with the risk of providing the very publicity that terrorist groups crave?

The Star reached Shirdon this week though a mobile phone messenger account it is believed he uses under the name Abu Usamah. At first, he declined to talk.

"Not interested in an interview. Sorry," he wrote early Friday.

Later in the day he responded again.

"The only thing I have to say to any reporter is tell your government its civilians will pay the price the war your government is waging against the Islamic state," he wrote.

"You are waging a war against people who see heaven in the barrel of guns. Do you honestly think you can win?"

He continued his threat saying, "The streets of Western cities will be filled with blood."

And he concludes: "The war has just begun."

Shirdon, a former Calgary resident, is just one of the stories of Canadians bound for Syria and Iraq that have raised fears at home. "Overwhelmed," is how one Western security official described the problem of foreign fighters. Much of the difficulty is simply verifying identities of those who may pose a risk — check any social media site and hundreds of profiles emerge of those purporting to support the Islamic State.

Even Shirdon — who first identified himself in a video earlier this year making threats against the U.S. and Canada while tearing up his passport — has been difficult to track.

It was widely reported in August that Shirdon was killed after rumours of his death surfaced on social media, only to have him appear in the VICE online video this week.

In the video, recorded Tuesday, a young man identifies himself as Abu Usamah and boasted about the attention he received from CSIS before leaving Canada.

"Someone actually came to me five or six days before I left," he said, purportedly speaking from Mosul, Iraq.

"I can't believe how someone that has extremist, terrorist ideologies is sitting in front of you and you didn't capture them," he continues. "The next time they saw me, they saw me ripping up my passport."

It is common practice for Canadian Security Intelligence Service agents, who do not have the power to arrest, to interview Canadians who come across their radar.

But what if this only makes the problem worse — giving wannabe jihadists the infamy they're looking for?

"These are disenfranchised, disaffected people seeking attention," said one security official reacting to the Shirdon comment about the CSIS visits. "Suddenly, he becomes a hero."

Although Canadians who seek the spotlight such as Shirdon may pose a danger to further recruiting through their propaganda, they are not the fighters who worry security services the most.

"Guys like him are seeking attention, the guy who thinks he can address Obama directly," says Mubin Shaikh, a security consultant who once acted as a CSIS operative to infiltrate the group known as the "Toronto 18," who plotted to attack local targets in 2006.

Yet the line between rhetoric and actions has always been the worrying unknown factor for so-called "homegrown" recruits — Western-raised fighters waging war abroad or at home. And what if the threats they deliver online resonate with disenfranchised youths here who decide to act?

World leaders addressed the issue of foreign fighters at the United Nations this week in an emergency Security Council session, with U.S. President Barack Obama stating that a suspected 15,000 citizens from 80 countries are now fighting in Iraq and Syria with the Islamic State (also known as ISIS and ISIL).

On Wednesday, Canada officially listed the Islamic State as a terrorist entity, and made support for the group an offence under the Criminal Code.

Ottawa also announced that passports would be invalidated for Canadians who travel abroad to fight, or are stopped before they leave Canada.

But the issue raised concerns among both civil rights advocates who feared citizenship would be arbitrarily stripped, and some security officials who asked if aspiring fighters would then direct their anger at home.

In Australia this week, an 18-year-old terrorism suspect stabbed two police officers before he was shot dead. He had been called in for questioning after reportedly flying an Islamic State flag at a shopping mall. His passport had earlier been revoked.

Amarnath Amarasingam, a post-doctoral fellow at Dalhousie University's Resilience Research Centre, is studying the Canadian cases to see if there are any patterns or

"red flags" to be identified among the recruits.

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Shirdon was one of at least six young Muslim Canadians who left Calgary for Syria, prompting questions of what may be the Alberta connection.

"What's unique is all of them hung out and came together at a time when they were reaffirming their faith or converting to Islam, they all at the same time decided that the imams were sell-outs and cowards, were weak," said Amarasingam.

"It's this group polarization idea, where they hung out together and radicalized themselves. I don't think it's a surprise that they all left within a month of each other."

Damian Clairmont, a recent convert to Islam, who was killed in Syria earlier this year, was identified as the most dominant personality in the group, said Amarasingam.

"It sounds like Damian was the most influential in convincing the others into this kind of view that we can't continue our lives in a non-Muslim country and that their brothers and sisters were suffering overseas."

Nathaniel Little, one of Shirdon's former friends in Calgary, said he was shocked seeing Shirdon's video interview this week, saying he doesn't feel Shirdon appreciates the seriousness of the situation.

"It seemed kind of playful. Like he didn't know how big of a deal this was," Little told the Toronto Star Friday.

The two had been friends since Grade 8 when Shirdon arrived with his family from Somalia.

"He had a very big heart. He was very loyal to his friends," said Little. "He wasn't exactly humble, he was somewhat cocky. You either loved that or hated that about him. But he always had a very good sense of humour."

They worked together at the local movie theatre and Orange Julius before Little said they drifted apart in Grade 12 when Shirdon started selling marijuana and was expelled.

"I do believe that he was very manipulated and brainwashed," said Little. "A lot of his other close friends are actually kind of happy to see that he's alive because they hope that one day he can recognize the mistakes he's made and maybe apologize to, say, his family for what he's putting them through," he said.

When asked in the VICE video how he was recruited, Shirdon answered: "No one recruited me. Actually, no one spoke a single word to me. All I did, I opened the newspaper, I read the Qur'an. Very easy."

In Hamilton this week, it was Mohamud's family and friends who were trying to dissect the 20-year-old university student's path to Syria.

Hussein Hamdani, a Hamilton lawyer who is acting as a spokesperson for the family, said in an interview that something had changed for Mohamud after his first year studying university.

"He went to high school, a brand new school, and ran for student council and won. He was gregarious, popular with the ladies, all these things. Something happened in York (University)," he said. "He looked at what was going on in the Muslim world and felt a lot of pain, especially for Syria. He started disassociating himself with the Muslim community and his friends and with his family."

In late July, during his summer break, Mohamud went to visit his father in Minneapolis, Minn., and instead of returning to his mother and extended family in Hamilton, Hamdani said he left from the U.S. for Turkey.

Soon after he sent a text saying he was bound for Syria and the family reached out to Hamdani, who contacted the RCMP.

"Unfortunately, it was too little too late."

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