Questions are being asked about how Cambridge Analytica, a data analytics firm, was allegedly able to harvest the data of more than 50m Facebook users. Chris Wylie, a former employee, told The New York Times, The Observer and Channel 4 News that the company was passed data collected by a separate company called Global Science Research. He says it used this information to create profiles on the respondents and their friends, and then targeted them with personalised political messages. Cambridge Analytica has denied using or holding Facebook data but this is how developers can pull data from the social network...