See LAT, "Amber Alert: Californians confused, angry and startled":
Residents across California were startled overnight by cellphones that came to life in screeches and buzzes, awaking some and unsettling others with the state's first Amber Alert via text message.Well, this is the first I've heard of it. Don't know if I'll opt out, but if they become really frequent, probably yes. I'll get the same alerts on TV within a few minutes.
Californians are no strangers to Amber Alerts, which are issued for critical child abductions. But for the first time Monday night, residents across the Southland experienced an Amber Alert issued via text message to their cellphones -- and got the full complement of a 10-second spurt of high-pitched noise and buzzing.
The message -- which included only basic details about a blue Nissan -- sent many customers into a tizzy of confusion, even anger. The text did not explain the circumstances.
Amber Alert Q&A: Why it happens, how to turn it off
The Amber Alert was issued after James Lee DiMaggio, suspected of killing Christina Anderson, 44, of Lakeside, allegedly kidnapped one or both of her children: Hannah Anderson, 16, and Ethan Anderson, 8.
Most newer phones are automatically set up to receive the alerts -- which look like text messages but are free -- meaning customers must contact their cell service provider to opt out of the program. Otherwise, customers will receive alerts tailored to geographic regions.
More at KABC-TV Los Angeles, "Amber Alerts on cellphones: A closer look."