Should the Canadian government strip the Khader family of citizenship and deport them?

Should the immigration officials that let them in be fired? The Khader family are friends of Osama Bin Laden and several members of the family have gone to Afghanistan to join the Taliban and fight against Afghanistan, Canada and its allies. Omar Khader was captured and is on trial for killing an American medic. Is treason sufficient cause to strip citizenship or are the warm and fuzzy Liberals correct that Omar should be repatriated and the Khaders be allowed to remain in Canada and live off our welfare system?