You could combine a cheese with a pretty good biological weapon, if you had the mind to.

"...some little old lady and a paunchy businessman..." That is exactly the way any rational terrorist would be likely to dress, surely, instead of "swarthy young men with accents"?

I've suggested that everyone flying on airlines or charter planes should have to hand in everything they've got, and everything they are wearing. Then travel wearing overalls or pyjamas issueed on the spot by the airline, and piuck up their stuff at the other end. If one result was to cut down the number of people who found it necessary to travel, all the better.