During a nearly four-hour grilling before Parliament Wednesday, Alexander Nix, former CEO of the now defunct data firm Cambridge Analytica, faced the ghosts of his past. In the green-carpeted room where the Digital, Culture, Media and Sport Committee interrogated Nix for the second time this year, the audience included Christopher Wylie, the former Cambridge Analytica employee who blew the whistle on the surreptitious harvesting of up to 87 million Facebook users' data; Carole Cadwalladr, th...