Last we heard of the federal government's Wireless Emergency Alert system, only Sprint had signed on to deliver the SMS warnings. Now, with the secured participation of all four major carriers and smaller regional operators, that gratis service is set to go live this month, covering nearly 97 percent of active mobile users. Using a "point-to-multipoint system" that targets at-risk subscribers, the National Weather Service, FEMA, FCC and Department of Hom
