In the Late Baroque masterpiece "The Swing," Jean-Honore Fragonard's painting from the 18th century, a young woman is being pushed on a swing by her elderly husband, simultaneously allowing her younger lover, who is hiding in the bushes, to peep under her skirt. A modern take on this, in the circles of online voyeurism, is called "upskirt": you look up a lady's skirt and take a photo...