Senators Quiz Facebook and Twitter

Facebook's Sheryl Sandberg and Twitter's Jack Dorsey answer questions from the Senate Intelligence Committee over US election interference by foreign powers. But Google is conspicuous by its absence. Plus we meet some of Berlin's most successful women tech founders, and we ask whether an algorithm can imitate someone's voice better than a human actor with the help of Donald Trump - kind of.

(Image: Facebook COO Sheryl Sandberg appears before the US Senate Intelligence Committee, Credit: REUTERS/ Joshua Roberts).