Florida police sounded the digital alarm Monday morning, broadcasting to some area residents on their mobile devices that the search was on for 2-year-old Denise Hernandez, missing from her Immokalee home.
But not all Southwest Floridians received the Amber Alert from the Florida Department of Law Enforcement.
The Commercial Mobile Alert System, a partnership between federal agencies and wireless carriers, went into effect in April. Based on location, type of emergency, phone, and carrier participation, critical alerts are sent out.
Only three occasions merit the messages, which are pushed to recipients not as a text or email, but as a message flash: those issued by the president or involving imminent threats to safety or life, as well as Amber Alerts, according to the Federal Communications Commission.
Customers don't sign up, but some carriers do. And not all phones are equipped to receive them.
The FCC suggests phone users discuss with their wireless carriers if they would like to opt out of the alerts. Presidential messages are the only ones that cannot be blocked, the agency noted.
The alerts are also focused on a "targeted area," unlike a text message. So cellphone users visiting an area may receive an alert if they are near the emergency.
Devices capable of receiving the alerts have a black and red label on the packaging that reads "wireless emergency alerts capable."
Justin Marecz, a Lee County father, didn't mind the mobile Amber Alert waking him up in the middle of the night.
"It's got to be out there because that one split second can save a kid's life," Marecz said