> whats' to stop someone from bringing a few gallons of chemical explosives in their backpack, mixing them in the lavatory, and blowing up the plane? Same thin

> whats' to stop someone from bringing a few gallons of chemical explosives in their backpack, mixing them in the lavatory, and blowing up the plane? Same thing that stops people from blowing up buses, trains cars, shopping malls, movie theaters, etc: not much. There just isn't a sufficient incentive and will to do such things.