Trump and the complexities of the cyber era

US intelligence chiefs told a Senate committee today Russia was more aggressive than ever in hacking to influence last year's US election. Donald Trump's denial of that claim has created a crisis of credibility, and agency leaders said today they want to be as public as possible. But Senators agreed that too much openness would threaten the lives of agents and waste the billions invested in worldwide cyber-spying. Is Trump onto something American spies don't know, or is he concerned that reports of Russian influence will de-legitimize his election?