Until about five years ago, this wouldn't have been possible. That's because it was only in December 2012 that the Federal Emergency Management Agency (FEMA) started to implement the Wireless Emergency Alert program, which is the one responsible for that aforementioned high-pitched tone.



The Wireless Emergency Alert program (also known as the Commercial Mobile Alert system) is used not just for Amber Alerts, but also to warn the public about natural disasters and imminent threats. Alerts can be issued by the National Weather Service, the office of the president of the United States and emergency operation centers. Think of it as the Emergency Broadcast System, but instead of appearing on radio and TV, it's on your phone.



Still, when most people think of these emergency notifications, they think of Amber Alerts, simply because they occur more often. The US Department of Justice started the Amber Alert program in 1996 in honor of 9-year-old Amber Hagerman, who was abducted and murdered in Arlington, Texas. The word "Amber" also stands for "America's Missing: Broadcast Emergency Response Plan." According to the National Center for Missing and Exploited Children, the Amber Alert program is "a voluntary partnership between law enforcement, broadcasters and transportation agencies to activate an urgent bulletin in the most serious child-abduction cases."





Before this, if you wanted to receive Amber Alerts on your phone, you had to opt-in with the National Center for Missing and Exploited Children. The program was simply called the Wireless Amber Alert program, and you'd have to not only sign up online but also specify which locations you wanted to get alerts from. Only around 700,000 people did this, so its reach was limited. Now, anyone with a cellphone receives the alerts by default.



While the previous Wireless Amber Alert program was SMS text-based, the current Emergency Alert program uses a technology called Cell Broadcast, which delivers messages to all phones within range of designated cell towers. It doesn't send the message to individual recipients, so it doesn't need to know your phone number and it doesn't need to know who you are. This way, the alert also won't be affected by voice and SMS text channels, which are typically more congested. Wireless Emergency Alert notifications are always free.



Each alert will contain up to 90 characters and is designed to be loud and unusual enough to capture your attention. The alert also typically only goes out to a certain geographic area where it would be of most use. So if a child was last seen in San Francisco, the Amber Alert would be sent to everyone in San Francisco, or at least in California. Sometimes the Alert is expanded to several states simultaneously, as was the case with missing 16-year-old Hannah Anderson from San Diego in 2013; authorities followed her abductor through California, Nevada, Oregon, Washington state and Idaho, sending out Amber Alerts in each state.



It's worth noting that not every missing-child report results in an Amber Alert. Not only is it reserved for "serious child-abduction cases," it's also provided only when authorities have enough information to put in the alert, such as the description of the child, the abductor or at least the type of vehicle they were last seen in. The goal of an Amber Alert is to "instantly galvanize the entire community to assist in the search for and safe recovery of the child."





Apparently, it works. Hannah, for example, was found in Idaho thanks to an Amber Alert warning on television. According to the National Center for Missing and Exploited Children, 857 children have been successfully recovered as a result of the Amber Alert program. However, only 38 were thanks to wireless emergency alerts, which is less than 5 percent of all recoveries (the rest were found through Amber Alerts on TV or the radio).



Still, that's 38 kids who otherwise would not have been found. Of those children, one is an 8-month-old boy in Minnesota, who was found because a neighbor saw the alert on his phone and recognized a Kia that matched the description. Another was a 7-month-old in New York City, who was recovered after the alert led to a tip sent to the police hot line.



You can disable these notifications if you wish. In Android, the settings will be under Cell Broadcast, while on iOS, you'll find the Government Alerts toggle under Notifications. But, seeing as these alerts could save lives, we suggest leaving them on.



Oh, and about that Amber Alert that I received last Friday? The child's name is Makai Bangoura, and he was found safe in Culver City, 400 miles from San Francisco. Alex Bastian of the San Francisco district attorney's office tells ABC 7 News that "the Amber Alert played a pivotal role" in his recovery.