Honestly, it is mostly a reaction to how society has evolved, for the worse. Rock and hard place.
The worst thing I have to hide is knowledge about my intentions, none of which are bad/illegal/immoral.
Scan away, I'd rather try to protect my children, other children from unscrupulous characters.
> The worst thing I have to hide is knowledge about my intentions, none of which are bad/illegal/immoral.
Correction: None of which are bad/illegal/immoral _right now_. The "I have nothing to hide" crowd will surely change their tune the moment any of their data starts to be used against them.