WASHINGTON – Officials say the U.S. government's efforts to determine which highly classified materials leaker Edward Snowden took from the National Security Agency have been frustrated by Snowden's sophisticated efforts to cover his digital trail by deleting or bypassing electronic logs.
Such logs would show what information Snowden had viewed or downloaded.
Government officials tell The Associated Press that investigators are wrestling with Snowden's apparent ability to defeat safeguards established to monitor and deter people looking at information without proper permission. The officials spoke on condition of anonymity because they weren't authorized to discuss the sensitive developments publicly.
The disclosure undermines the Obama administration's assurances to Congress and the public that the NSA surveillance programs can't be abused because its spying systems are so aggressively monitored and audited for oversight purposes.