According to numerous media sources and eyewitness accounts, the person you've known for almost a full decade, the one who seemed like a well-adjusted and productive member of society, is also shadowing as a person who writes long posts on LinkedIn talking about things like maximizing client engagement and how to nail job interviews at marketing firms. It's like your friend is secretly a completely different person-an alter ego who has completely immersed herself in the bizarre and alien social ecosystem of LinkedIn.