DALLAS, TX - JUNE 06:  A general view of the skyline of downtown Dallas, Texas as the American Airlines Center can be seen the night before Game Four of the 2011 NBA Finals on June 6, 2011 in Dallas, Texas. NOTE TO USER: User expressly acknowledges and agrees that, by downloading and/or using this Photograph, user is consenting to the terms and conditions of the Getty Images License Agreement  (Photo by Mike Ehrmann/Getty Images)
Hacker sets off 156 emergency alarms
Dallas residents were jolted out of bed after a hacker triggered all the city's emergency sirens, setting off a wave of panic and confusion.
1:24 • Source: KTVT
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DALLAS, TX - JUNE 06:  A general view of the skyline of downtown Dallas, Texas as the American Airlines Center can be seen the night before Game Four of the 2011 NBA Finals on June 6, 2011 in Dallas, Texas. NOTE TO USER: User expressly acknowledges and agrees that, by downloading and/or using this Photograph, user is consenting to the terms and conditions of the Getty Images License Agreement  (Photo by Mike Ehrmann/Getty Images)
Hacker sets off 156 emergency alarms
1:24
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• Source: KTVT