do you really think that if someone wanted to cause a terrorist attack on an airline, that they would be that bothered if they travelled on there own name or not. They probably intend to die anyway.
domestic flights dont require photo ID (dependant on airline) so why does someone without a passport suddenly become a terror risk.
after all, the pax all go through the same security screening process regardless of passport or even boarding card (cos they get airside without them too).