Ramaa Mosley, a Los Angeles director and mother of two, was driving in her car when she heard the news on the radio. Nearly 300 schoolgirls in Nigeria had been kidnapped by armed extremists.
"I started weeping and I raced home," Mosley said. "I looked on the Internet and I found some news in Africa that confirmed it, but couldn't find anything else in the United States."
Five days had already passed at that point since the mass abduction on April 14. The militant Islamist group Boko Haram later claimed responsibility for the kidnappings. Boko Haram means "Western Education is a Sin," and in a video message, a leader of the group threatened to sell the schoolgirls and force them to marry.
"I believe that we've been desensitized to what goes on in Africa," Mosley said. "To think that, in 2014, school girls can be kidnapped from their schools is barbaric."
Mosley said that she decided to transform her initial feeling of powerlessness into action. She thought about getting on a plane to Chibok, Nigeria, where the students were kidnapped, but her 11-year-old daughter begged her not to go out of concern for her mother's safety.
"She asked me to try to think of a way to help from here," Mosley said. "I decided what I would do is that I would put out a call on social media."
WATCH: US Mom's Social Media Push to Save Nigerian Kidnapping Victims
But Mosley, a director of commercials and documentaries, did not have much personal experience with social media. She had heard her daughter use the word "hashtag," but she did not even really understand what it meant.
"I thought it was sort of a phrase that young people use," she said. "Then I realized recently that a hashtag is like a call. It's like a call out to the world and it's also an amalgamation so you can pull together information, put that information in and get information back."
Mosley knew that mothers in Nigeria were chanting, "Bring back our girls," at protests, so she borrowed the slogan for Twitter.
"I started shouting it to Barack Obama, my senators in California, to any celebrity that I could think of," she said, "and within a few hours, I started getting responses."
WATCH: Kidnapped Nigerian Girls: Social Media Reacts
The phrase has now been repeated on Twitter more than 800,000 times, including by celebrities Kerry Washington and Chris Brown. On Sunday, Hillary Clinton tweeted, "Access to education is a basic right & an unconscionable reason to target innocent girls. We must stand up to terrorism. #BringBackOurGirls."
"When Hillary Clinton finally tweeted back #BringBackOurGirls, I jumped up and I cheered," Mosley said. "I realize that it seems like a hashtag is a trivial thing. But actually it's not. It's an SOS to the world."
Mosley also created a Facebook page to amalgamate information about the story and give people suggestions about ways that they can take action. The page now has more the 43,000 likes.
"I am living this 24/7," she said. "This has consumed my life and I believe it will until the girls are rescued."
Last night, Mosley attended a protest in Los Angeles, where about a hundred people gathered and chanted, "Bring our girls back." She said that some of the people who contact her through Facebook have been asking her for permission to organize protests.
"I say this is for you to give yourself permission to do," Mosley said. "Every one of us should be marching and protesting."
'Bring Back Our Girls' Becomes Rallying Cry