World leaders express concern about reports of mass surveillance by the US     BY AYEE MACARAIG  ASIA PACIFIC 10/23/2013 7:26 AM  | UPDATED 10/23/2013 8:43 AM  Rappler.com 'ALARMING CHALLENGES.' World leaders express concern about reports of mass surveillance by the US at the opening of the Internet Governance Forum in Bali, Indonesia. Photo by Ayee Macaraig/Rappler More