Through a widely-reported poster campaign (see inset), "We're a Culture not a Costume" is a sincere and laudable effort to draw awareness to the perpetuation of prejudice through racist Halloween costumes. Not some big-budget ad campaign either; a project that came out of a smart and resourceful student group at Ohio University.
But as with all things sincere and laudable, the internet has turned it into lulz.
The originals really are great, though. It's nice to laugh at Daleks and golden retrievers, but the message of the original campaign is a meme that really does deserve spreading. Kudos to the designer, whoever he or she may be!