I just had a big dose of that this morning, getting my tool bag flagged by TSA, which I honestly expected, and told my calipers were not allowed (because maybe I'm going to hijack a plane by threatening to measure it??) but having my very sharp broaching tools, which could actually maybe do some damage as a weapon, completely ignored. And then, the second time through, after checking the calipers, having my watch case opener taken because it sort of looks like a knife, even though it's completely dull with no sharp edge.