The other factor is that people who go through that process typically arrive in Canada, claim refugee status, and in many cases they'd have a plausible rationale for that, so that if they were sent back they could be in jeopardy. It could be political jeopardy or what have you. But a terrorist or an alleged terrorist who's being detained under a security certificate, the ones who are currently detained at this point in time, still in Canada.... If they've gone back those issues have been dealt with, I guess, and hopefully they live the happy life they're after.
But for the ones who are currently being held under a security certificate, have you researched the arguments they presented as to why they could not go back to their own home country? I would suspect that typically they haven't arrived in Canada claiming refugee status. They probably come here.... But I don't know that for sure.