Federal agencies report increasing cyber-intrusions into government computer networks, perpetrated by a range of known and unknown actors. In response, the President, legislators, experts, and others have characterized cybersecurity as a pressing national security issue. Like other national security challenges in the post-9/11 era, the cyber threat is multi-faceted and lacks clearly delineated boundaries. Some cyber attackers operate through foreign nations military or intelligence-gathering operations, whereas others have connections to terrorist groups or operate as individuals.