A militant conspiracy to attack Canadian targets was an unrealistic "jihadi fantasy" that was deliberately hidden from a young man on trial for his role in the alleged plot, an Ontario court heard Thursday.

The accused is one of 18 people in the Toronto area who were arrested under Canada's fledgling anti-terrorism laws in 2006. In the case, which attracted international attention, police alleged there was a homegrown militant plot bent on causing havoc in Canada, including by attacking Parliament Hill, beheading politicians and truck-bombing various targets such as nuclear power plants and RCMP headquarters.

The man currently on trial, who was 17 at the time of the alleged offences but is now 20, has pleaded not guilty to terrorism-related charges, including that he aided a militant group by shoplifting camping supplies and walkie-talkies.

In closing arguments in Brampton on Thursday, defence lawyer Mitchell Chernovsky said the Crown had failed to prove the group was, in fact, a real militant cell.

While the group's leader vowed to "cripple Canada" and began recruiting people to implement his scheme, even the Crown's star witness testified the man was little more than a self-aggrandizing braggart.

"He lied about everyone and everything," Chernovsky told Superior Court Justice John Sproat.

"One wonders if he was even capable of telling the truth."

Even if the man did have genuinely nefarious ideas, his "complete ineptitude" precluded anything from ever happening, the lawyer said.

"All of this is a fantasy, a delusion, with zero probability of ever being implemented," Chernovsky said.

In fact, the defence lawyer said, another of the leaders broke away from the group because he knew nothing would ever happen.

While that leader may really have had violent plans in mind, there is almost no evidence tying him to his client, Chernovsky said.

Neither the accused in the current trial nor any of the adults still to be tried under Canada's fledgling anti-terrorism laws can be identified by court order.

Charges against seven of the people arrested in 2006 have since been stayed or dropped.

The court has heard the accused was an enthusiastic participant in camps the Crown says were intended as preparation for the attacks.

Chernovsky pointed to evidence the leader went to "extreme lengths persistently, without exception, without fail" to keep his recruits "on the down low" about his plans.

Chernovsky noted that even the Crown's own star witness testified the accused was unaware of the alleged plot.

The young man, a Hindu convert to Islam, was a "naive" teenager with no reference points in the Muslim religion or geopolitical reality, the lawyer told the court.

The court has heard he had a troubled relationship with his family and looked up to the leader as a mentor in his new religion.

Closing arguments were expected to continue on Friday.