The head of Britain’s domestic spy agency MI5 said today that China is carrying out cyber-espionage, stealing technology secrets and trying “to interfere covertly in UK public life.” Ken McCallum spoke in a rare public appearance saying, “Do Chinese state actors present a UK national security threat? And the answer is, of course, yes, they do, every day.” The comments will bring more attention to the failed prosecution of two British men accused of spying for China. The World’s Matthew Bell reports.