It exists, but it's not a simple as making use of something from another culture.
A white girl with corn rows is not cultural appropriation. A white girl with corn rows that does not understand the struggles of the people she's borrowing her hair style from, THAT is cultural appropriation. A white person doing rap is not cultural appropriation. White people being unfairly overappreciated for rapping, while black rappers are largely disregarded for "sounding agry" or "being too graphic or rude", THAT is cultural appropriation. Macklemore got it right in White Privilege II, when he mentions that mother that says he's the only rap she let's her children listen to. Those children consuming rap exclusively when it comes from a white person, THAT right there is them appropriating rap.
Yes there's a lot of hypocrisy in this idea. It's completely opposed to any form of cultural evolution and displays a form of conservatism rarely espoused by those who see it as a major problem. Its nothing but posturing. There are instances where there is validity in the complaints but most of the time it's not hurting anyone.
