I've opted out every time I traveled prior to the introduction of (opt-in, non-frequent flyer based) Precheck, so 8-10 times per year from 2010-2014(?) and never had a notable issue.

As the other child comment says, rights atrophy if you don't exercise them.

Why not? Rights are like muscle. They atrophy without exercise.

I opt out every time, or did before I got precheck (I know, irony). I never had anything remotely like this experience, and my shaving soap has set off the gas chromatograph machine twice. I still bring it with me when I travel (it doesn't always trigger the machine, but that's a different discussion about the pointlessness of a machine with a lousy false positive rate being used to test for something with a vanishingly small prior).

My secret? I'm an average looking White Male in the US. Nobody ever thinks _even for a second_ that I could be a threat. Last time my soap got me taken to secondary screening, TSA left me alone in the room with their walkie talkie charging station. With all my stuff. Unsupervised.

I always do it.

I don't trust those machines.

And yeah i'm white, i don't have any problems at security. People think i'm arrogant white dude before they think i'm a terrorist.

Exactly, all it does is dial up the suspicion level.