U.S. issues guidelines for responding to major cyber attacks

By Dustin Volz and Karen Freifeld WASHINGTON/NEW YORK (Reuters) - The White House issued new instructions on Tuesday on how government agencies should respond to major cyber security attacks, attempting to combat perceptions the Obama administration has been sluggish in addressing threats from sophisticated hacking adversaries. The announcement was made amid suspicion in the U.S. government that hackers working for Russia may have engineered the leak of emails stolen from the Democratic National