Twitter introduces an alert system for emergencies, disasters

Twitter, which is preparing for its initial public offering, said it will help users receive special alerts from government agencies and aid agencies during emergencies.

Users who sign up will receive smartphone notifications via the Twitter app as well as SMS text messages - assuming they agree to handover their cell phone numbers - from any of several dozen agencies who have signed on to the program. The Federal Emergency Management Agency, Tokyo's Disaster Prevention service and the World Health Organization are among those participating.