VoIP phone hackers pose public safety threat

Hospitals, 911 call centers and other public safety agencies can be shut down by hackers using denial-of-service attacks.The demand stunned the hospital employee. She had picked up the emergency room's phone line, expecting to hear a dispatcher or a doctor. But instead, an unfamiliar male greeted her by name and then threatened to paralyze the hospital's phone service if she didn't pay him hundreds of dollars.