According to the figures in this[1] article, whites are technically under-represented at Twitter relative to their percentage of the general population, yet both it and the NPR article take for granted that there is a lack of ethnic diversity at Twitter and other tech companies, despite non-whites collectively being over-represented at them.
While certain minorities (blacks, Hispanics) are indeed under-represented at tech companies like Twitter, others (Asians) are over-represented, and to such a degree that whites actually end up under-represented. Yet a careless reader could easily be misled by these and other articles into believing that whites are crowding out minorities, which is demonstrably not the case.
I doubt this deception is accidental.
[1] http://www.motherjones.com/mojo/2014/07/twitter-diversity-st...