If law enforcement authorities have their way, Facebook users soon will use the site for more than sending messages to friends and playing Farmville.

Those users also can now help find a missing child.

Amber Alerts will be distributed on Facebook in an effort to spread the word faster about missing children, law enforcement and Facebook officials announced Wednesday.

Fifty-three Facebook pages -- one for each state, the District, Puerto Rico and the U.S. Virgin Islands -- have been set to post the alerts. When a state issues an alert for a missing child, people who are fans of that state's Amber Alert page will be notified. Authorities hope people who see the messages will share the news on their own Facebook pages.

"They can share that information with their friends in a way that immediately spreads the word that a child needs our help," said Chris Sonderby, Facebook's lead security and investigations counsel and a former federal prosecutor.

Allowing Facebook's 500 million users to opt-in to receive the alerts is an "important extension of the national Amber Alert program," said Ernie Allen, president of the National Center for Missing and Exploited Children.

About 800,000 children are reported missing each year, according to NCMEC. Amber Alerts are issued in only the most serious cases. Thursday is the 15th anniversary of the abduction and slaying of 9-year-old Amber Hagerman, for whom the system is named.

The first Amber Alert plans were developed in Texas a year later, and the system is credited with bringing 525 children home safely, said Laurie Robinson, assistant attorney general in the Office of Justice Programs for the Department of Justice.

Local authorities say social media has become a key tool in alerting the public about safety matters, including missing people.

Virginia State Police Superintendent Col. Steven Flaherty said authorities used social networks to provide updates and ask for help when a 12-year-old girl was reported missing after her mother was found dead in Roanoke in December. Police received more than 1,000 tips from across the country before the girl and her abductor were tracked down in San Francisco.

"Social media certainly enabled law enforcement to reach beyond our borders, our normal footprint," Flaherty said. "I can only dream what we'll be able to do now with 53 Facebook pages."

The District's Amber Alert Facebook page is facebook.com/AmberAlertDC, Maryland's is facebook.com/AmberAlertMD and Virginia's is facebook.com/AmberAlertVA.