"I haven't heard of any reports of undocumented Canadians"
No but you have heard stories of home grown terrorism in Canada. It seems that only a week ago home grown terrorism in Canada was the lead story in most newspapers everywhere. But the story seems to have disappeared and replaced with stories about Canada that tend to give Canada its soft image.
So, when you say undocumented Canadians, how many would it take to do incredible damage?
If Canada has that problem, there are plenty of more Western countries with same problems, plenty of AQ operatives here in Ireland (and no doubt getting help from Sinn Fein/IRA).