The AMBER Alert program is a national child abduction alert system. AMBER stands for "America's Missing: Broadcast Emergency Response", and it was named in honor of Amber Hagerman.
Active AMBER alerts can be seen at the National Center for Missing and Exploited Children's AMBER Alert Program webpage.
There are several ways to get notified of AMBER Alerts,. More information can be found on the National Center for Missing and Exploited Children's How Do I Receive AMBER Alerts? webpage.