Vanity Fair: Fresh off a $70 million investment in audio-streaming service SoundCloud, Twitter announced Monday that it has purchased Magic Pony, a British artificial-intelligence startup, for a reported $150 million. Magic Pony is the third machine-learning start-up Twitter has purchased in as many years. Prior to buying up Magic Pony, Twitter bought A.I. start-ups Madbits in 2014 and Whetlab a year later.