Comment by vkou

> . This reminds me of the chemical swipes done on your bags to detect explosives. Those swipes can only detect a narrow set of explosive chemistries and everyone knows it.

Meanwhile, you get swabbed, the machine produces a false positive, the TSA drone asks you why the machine is showing a positive, you have no fucking idea why, and they just keep swabbing until they get a green light and everyone moves on with life.