What items? Drugs and bombs that someone managed to sneak past security already? In that case isn't the real problem improper inspection? What if the proposed mad bomber, after having successfully managed to sneak all these explosives past security, and hoping to transfer the explosives from his own suitcase to that of a stranger on a specific flight who went to the bathroom, in plain view in front of everybody sitting there waiting for that flight to board, finds that no one has gone to the bathroom without their luggage on that day? Wouldn't that ruin his plan? Not a great plan to be relying on someone on a specific flight going to the bathroom and a whole room full of people somehow not noticing a guy openly transferring an entire suitcase full of explosives from one suitcase to another. Wouldn't one of the other passengers waiting for the same plane at this point say hey wait a minute, this dude here is transferring a bunch of explosives from one suitcase to another! Maybe I should say something!

Yeah that's the argument. Someone's gonna plant the explosives while I'm in the bathroom.

You know what? That's never going to happen, it's never happened, and it's a crazy thing to imagine would ever happen. It's just hysterical paranoia and fearmongering to go on about someone planting a suitcase full of explosives in another suitcase in plain view of everyone during a few minutes when some guy is in the bathroom.

This fear and paranoia is actively harming society. Parents won't let their children walk to school or a friends house or play in the yard because they are convinced the children will be abducted by a mad kidnapper. So their kids become waddling obese paranoid kids fixed on their screens, depressed, miserable, high blood pressure, having been raised in a culture of fear, years shaved off their lives from the stress.

All these irrational things, none based on facts or reasonable threat assessment, are actively harming society, and the people pushing this fear are doing it intentionally. But to what aim?