What exactly is a 'Karen' and where did the meme come from?

In 1990, 16-year-old Karen Williams went out in the remote mining town of Coober Pedy. She has never been seen or heard from again. Lavene, who is Karen's first cousin-once removed, says the family still holds hope for Karen's return. "They've had her for 35 years. Don't cheat us. Give her back to us so we can give her the rite of passage in relation to our culture, our faith, our understanding ..." To read more about what happens when someone vanishes and the questions left in the wake, click h