As an experiment to see just how uneducated and ignorant modern America is, I posted a new default picture: Michaelangelo's David. This has been a revered work of fine art for centuries. It is displayed with the utmost of respect, and is a beautiful example of art from the Italian Renaissance, not to mention that it's a representation of a biblical character - David from the David and Goliath story. I want to see how long it takes for some bible thumping, uneducated schmoe to flag it as NSFW.
Any educated person will see it as a work of beauty (or, even if you don't like it, will accept it as a piece of art, revered by others). Only the uneducated American moron, who spouts nothing more than Jesus and War (along with a hefty dose of hate of Muslims) thanks to a fascist government would mark this work of fine art as NSFW.
Anyone who marks this photo as NSFW is also likely to be someone who wants to burn books and lynch anyone different from them.