(CNN) — Top telecom executives met with US national security officials at the White House on Friday as concerns mount over a long-running Chinese cyber-espionage campaign that has targeted some of the most senior US political figures in the country. The hackers burrowed deep into some major US telecom providers to spy on phone calls and text messages and have proved difficult to kick out of some networks, people briefed on the matter said. The meetings were a chance for telecom executives to