Two of the most notable recent terrorism attempts by Canadian nationals, courtesy of the CBC:
In the summer of 2006, police carried out a massive anti-terrorism sweep in southern Ontario. Seventeen people — 13 adults and four youths — were arrested in a series of June raids. An 18th individual was detained two months later.
Normally referred to as one case, the so-called Toronto 18 in fact encompassed two plots, says Bill Gillespie, security correspondent for CBC News.
One was a plan to bomb the Toronto Stock Exchange and other prominent buildings. The other, Gillespie says, was "the attempt to create a large al-Qaeda type cell in Toronto — to arm themselves with weapons, and then to create some sort of mayhem that would scare the Canadian public into withdrawing troops from Afghanistan."
Seven adults admitted guilt in the affair. The courts also convicted four men, one of whom was a minor at the time of his arrest. Charges against seven other individuals were stayed or dropped.
[T]wo Canadians linked to al-Qaeda and killed while staging a bloody attack on an Algerian gas refinery earlier this year  were former high school friends in their early 20s, one from a Greek Orthodox family, and both from a comfortable middle-class London, Ont., neighbourhood.
A special CBC News investigation has confirmed the two al-Qaeda linked militants were Xristos Katsiroubas, 22, and Ali Medlej, who was believed to be about 24 years old at the time of their deaths.
The attack by the two Canadians and 30 other militants linked to al-Qaeda left more than three dozen refinery workers dead, the final 10 of whom were reportedly tied to gas plant piping and killed in a massive bomb blast.
Sources say it is likely Katsiroubas and Medlej intentionally blew themselves up in the blast; one of them could be only identified by DNA testing.