How spy agencies ferret out moles

last updated 8 January 2015

The federal government spends millions of dollars every year hunting for insider threats in its intelligence agencies, according to a classified budget document leaked by former NSA contractor Edward Snowden last week. According to the CIA, one in five potential employees whose backgrounds raised questions had “significant terrorist and/or hostile intelligence connections” to groups like Hamas, Hezbollah, and al Qaida. After the 2010 WikiLeaks scandal, the NSA reinvestigated at least 4,000 suspicious staff members, scrutinizing their computer activity for “anomalous behavior.” But contractors such as Snowden were not included in those investigations.