Adele, the singer, was photographed at the Nottinghill Carnival (a massive Carribean street festival over the August bank holiday in London) with her hair in Bantu Knots and wearing a bikini top in the colours of the Jamaican flag. As soon as it was on twitter the you started getting tweets from Black Americans about cultural appropriation, but this was met in turn by fierce opposition from African and Carribean post…
This is usually referred to as cultural exchange or sharing of culture.
The fact that cultures shouldn't be shared is indeed a new phenomenon, one that I personally don't agree with.