Department of Homeland Security Secretary and retired General John Kelly said last week that hackers are "a tremendous danger to our American way of life" yesterday in his first public speech as secretary.  "They target our critical infrastructure," he warned. "Systems throughout America are being bombarded on a daily, even hourly basis — our water treatment plants, our transportation systems, our electric grid, our financial sectors and everything in between."  The Secretary asked audience members to think about "what would happen if a major American city lost power," navigation systems went dead or the stock market crashed under pressure from a sophisticated cyberattack.