think the world is theirs for the taking

Here is a post from Goddamazon, on Tumblr, explaining the original purpose of the "we're a culture, not a costume" poster campaign. It is a very clear, well-presented lecture on the broader topic of cultural appropriation by white people.*

The context is that a college student (read here) has started up putting posters on Tumblr about cultural appropriation in Hallowe'en costumes. The posters say "We're a culture, not a costume. This is not who I am, and this is not okay". There is now a backlash parody meme where people make fun of these posters. They obviously didn't get the message.

( video )

What she says, about and in the video:
( here )

*As always, and as she explains, this means "some white people" not "all white people".