Washington DC, Wed Jun 26, 2013 - Even as US intelligence agencies and their global partners assess potential damage from Edward Snowden's disclosures about surveillance programmes, militants have begun responding by altering methods of communication, a change that could make it harder to foil attacks, US officials say.
Intelligence agencies have detected that members of targeted militant organizations, including both Sunni and Shi'ite Islamist groups, have begun altering communications patterns in what was believed to be a direct response to details on eavesdropping leaked by the former US spy agency contractor, two US national security sources said.
The officials said it was too early to tell whether the recent changes in communications methods had caused a loss of critical intelligence or if there was now a greater risk of missing warning signs about future attacks.
"You don't know what you lose until after you've lost it," one of the sources said.
The charge that Snowden's leaks are causing damage, made by officials speaking on condition of anonymity, comes as the Obama administration mounts a campaign to pressure Russia to extradite him. Russian president Vladimir Putin on Tuesday confirmed Snowden was in the transit area of a Moscow airport, but ruled out handing him to Washington
One US telecommunications expert said privately that the militants' latest adjustments likely included reduced electronic transmissions and more frequent switching of cell phones while they seek new encryption methods.
Largely using written messages and trusted couriers, al Qaeda leader Osama bin Laden hid for years until he was killed by US forces in 2011. He advised militants to exercise extreme caution over electronic communications. Thumb drives and sim cards used to carry information should be destroyed after use, he told them.