They're at your laundromat and in the produce aisle. They're on the subway and at the food court in the mall.
They're the twerking flash mob and they've taken over San Francisco.
A new video by Simple Pickup shows a trio of ladies twerking on cable cars and with a homeless man, twerking in Union Square in front of a baby and -- our personal favorite -- twerking to the gentle sounds of a classic Chinese orchestra in Chinatown.
The video contains only a brilliantly simple description: black girls twerk in front of confused white people.
Who are these twerkers? Who knows? Who cares? We can't get enough of them.