I'm not interested in celebs speaking out about Ferguson. Celebs aren't obligated to speak out about incidents. There is a larger trend that the author is addressing. Ignore the specific artists mentioned and see the trend over the past 50 or so years.
The writer is correct that there are and always have been white celebs (regardless of talent or lack thereof) who adopt or perhaps mock the more stereotypical aspects of Black culture; and then these white celebs disappear to their Ivory Tower when it isn't about making money.
That has happened for generations when older white artists were mimicking Blacks or making money from Black audiences but when any type of social issue comes about (even before the Civil Rights Movement) these artists conveniently remembered their whiteness.
She's absolutely correct in that aspect. But when she chooses celebs that are such lightning rods for assery, just to get more views (i.e. way more people are going to read an article on Justin Bieber than on Bobby Caldwell) she waters down her point.
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It is all 33girl's fault. ~DrPhil