Originally Posted by RichardKenner

I'm having trouble understanding why a buzzing in a backpack would be the least bit suspicious. The only possible explanation was some small appliance that wasn't turned off. I can't think of anything that could be a possible hazzard that would be continuously buzzing. Neither a weapon nor a bomb component would do that. I'd certainly have mentioned it so that the passenger didn't arrive with a dead battery, but a threat? I don't see it.