Sia is usually shy about showing her face, however she showed more than what we're used to on her Instagram page...her bare bum!
She found out some creep was trying to sell her nude photos of her to her own fans, so she beat them at their own game, by posting them before they could. The photo shows Sia's backside on a balcony in the buff.
In her caption she wrote "Someone is apparently trying to sell naked photos of me to my fans. Save your money, here it is for free. Everyday is Christmas!"