Four hours after learning about Saturday's devastating earthquake in Nepal, I received a Facebook notification I had never seen before: Sonia, a journalist friend based in northern India, was "marked safe." An hour later, the same notification about a different friend popped up. Then another. Soon, several of my friends wrote that they, too, had learned via this strange new notification that their friends in Nepal were okay.
A few hours later, the mystery was solved. On Saturday afternoon, Facebook CEO Mark Zuckerberg announced on his timeline that the notifications came from Safety Check, a service the company launched last fall. "When disasters happen, people need to know their loved ones are safe," he wrote, "It's moments like this that being able to connect really matters."
When activated, Safety Check locates Facebook users near a disaster site through the city they list on their profile, or from where they last used the Internet. Users then receive a notification asking to confirm that they're safe or to say that they weren't in the affected area. Those who choose "safe" generate a notification to their friends and followers, who can track how many of their friends were affected.