US grapples with how to retaliate in cyber attacks

In the murky world of computer espionage, the US faces hard choices on how to retaliate when government or privately owned networks come under cyber attack, senior military and intelligence officials said Tuesday. As the administration grapples with how best to defend its computer networks, debate is raging over how far the U.S. can go in pursuit of cyber criminals, and even what constitutes a digital act of war. The most immediate challenge is identifying the hacker, terrorist or enemy nation that launched the attack in vast and anonymous cyberspace, officials said. That hurdle is complicated by privacy debates over how deeply the government can wade into privately owned systems to investigate threats, and how it should handle attacks against a company, as opposed to a federal agency.