A flyer tried to get through DCA security wearing a "silver Banana Republic sweater with shiny speckles," thereby confounding the $150,000 full-body scanner and drawing one of TSA's patented happy pat-downs. There are a lot of problems with silver Banana Republic sweaters that have shiny speckles - a lot - but overwhelming the US's frontline airline security system shouldn't be one of them.
The rest of the WaPo article is filled with First World Problem whining about how the 3-1-1 rule precludes specialty hair products. There's not much there. We're only including it at all because we like the idea of TSA agents being distracted by shiny things, which is a joke we're pretty sure we've actually made.
That said - and on a more serious note - there's a genuine upshot to this Japanese video. We've already done several posts about this exact issue. There's no such thing as genuinely "random" screening. Someone is always making a decision, either based on a profile that's locked in by superiors up the ladder, or based on an individual judgment made at security. And as long as we let individual agents make their own decisions, we're going to get stories - fair or not - about "blonde cheerleaders" and "African-American businessmen" who get pulled aside and harassed for reasons having nothing to do with security. See here and here and here.
Or just watch the video, which is frankly much more entertaining.