Terry Gross

Christopher Wylie was a research director at Cambridge Analytica. When he joined the company its goal was countering extremists who were using social media to recruit followers. But then the company began collecting personal data from Facebook users, and used it to target people susceptible to conspiracy theories and disinformation during the 2016 presidential campaign. Wylie left the company and became a whistleblower.

Counter tenor Anthony Ross Costanzo sings in what's considered a woman's range - in the range of the castrati, men who maintained their high voices by being castrated before puberty. He's about to star in the Philip Glass opera 'Akhenaten.'

President Trump made building a border wall between the U.S. and Mexico a cornerstone of his 2016 presidential campaign. But when, after the election, efforts to build the wall stalled, he turned to other possible options — including constructing a trench filled with snakes and alligators — according to a forthcoming book.