Sia is offering a holiday gift that's one part diss and one part whip-smart self-promotion: a picture of herself in her birthday suit. The 41-year-old singer released the combination preemptive strike/album promotion after she found out someone was trying to sell naked photos of her, People reports, said to be taken on the sly while she was walking around in the buff outside a residence. "Someone is apparently trying to sell naked photos of me to my fans," Sia tweeted Monday, along with a photo of her uncovered backside. "Save your money, here it is for free. Everyday is Christmas!" Some may have been surprised by her move, as the Guardian notes Sia is "notoriously private," but it just so happens Everyday Is Christmas is also the name of her upcoming Christmas album, so … +1 Sia? (More Sia Furler stories.)