For weeks after the disturbing news broke that Islamist extremists had kidnapped hundreds of schoolgirls in Nigeria, people wondered why the story wasn't the center of global attention. "Why is the media ignoring 200 missing girls?" Mary Elizabeth Williams wrote at Salon last week. "If it had happened anywhere else, this would be the world's biggest story," Frida Ghitis wrote for CNN on Monday.

In the past few days, however, the situation appears to be different. Not only is the story a major news item, but, on Tuesday, the United States pledged to send a team, including military personnel, intelligence and hostage negotiators, to help find the girls.

So what changed? Although there are no doubt many other factors in the visibility of the Nigerian girls story, one factor does stand out: the remarkable rise of #BringBackOurGirls. It seems clear that the hashtag is making some kind of impact. But will that impact actually be positive for Nigeria? Or are Western tweeters falling into a trap of ineffectual, or even counter-productive, slacktivism. The answer to that is not clear.

"Bring back our girls" only became a slogan in a speech from the Vice President of the World Bank for Africa Oby Ezekwesli on April 23. It has now spread into a truly global social media phenomenon, with analytics firm Topsy reporting that the hashtag has been  mentioned more than 1 million times in the past month, with a huge spike over the past week. Now, protests that make use of the slogan have appeared in international capitals, and Amnesty International recently set up a Tumblr to collect images featuring the message. Chelsea ClintonChris Brown and Amy Poehler are just some of the celebrities who have lent their name to the cause.

Let's point out the obvious here: The story is horrific.  On the night of April 14, members of the extremist Islamist group Boko Haram burst into the dorms at Chibok Government Girls Secondary School in Borno State, Nigeria, and kidnapped hundreds of schoolgirls. With three weeks now passed, and, according to some accounts, 276 girls are still missing, there seems to have been little progress on rescuing them.

Right now, however, it is still unclear how exactly a hashtag can help. Nigerian American author Teju Cole fired off a series of tweets last week that cast doubt on whether greater international attention could actually make a genuine difference. "Part of the horror was that the girls were ignored," Cole wrote. "An opposite problem now is CNN's heavy sensationalist interest."

Over the past few years, the low personal investment required from social media campaigns has led some to label them "slacktivism": i.e., a lazy, less effective form of activism. Many readers will no doubt remember the Kony 2012 viral video, which saw U.S.-based organization Invisible Children calling for Ugandan militia leader Joseph Kony to be stopped. While Kony 2012 is said to have been one of the biggest viral successes ever and certainly led to U.S. political attention on Kony in the short term, its effects appears to have waned and Kony remains free. Cole himself argued that Invisible Children was part of the broader "White Savior Industrial Complex" – and added last week: "Boko Haram is irreducibly complex. Makes Kony look like child's play."

However, there are important differences between Kony 2012 and #BringBackOurGirls: While Invisible Children was based in California, the Nigerian effort grew organically from within the country. And while Kony 2012 had one specific aim, the way that #BringBackOurGirls has progressed means that its aims remain organic, and fluid.

"Of course it had to begin here, those abducted, their parents/relatives, the victims of Boko Haram's terror are Nigerians," Nwachukwu Egbunike, a Nigerian journalist who has been following the movement, told me in an e-mail. "The prevailing terrorism is not happening on the streets of New York but in Abuja. It is a Nigerian story and Nigerians bear the scars of this ugly story. "

"I don't think #BringBackOurGirls is anything like Kony 2012, but I'm interested to see if it could turn into something broader," Laura Seay, a political scientist with Colby College, explains. "Nigerians have long known that their country has problems due to corruption and incompetence among governing leaders, but most people just go about their day-to-day lives without having the sense that they can do much to stop it. The Chibok girls' crisis — combined with the attacks on Abuja in recent weeks — seems to have touched a nerve and catalyzed protest in a way I haven't seen before."

Domestically, the #BringBackOurChildren campaign isn't aimed at the perpetrators of the attack: Boko Haram seem unlikely to be swayed by tweets (remember, their name literally means "Western education is sinful"). It's aimed at the government who have appeared inept the Boko Haram problem for too long. Critics of Goodluck Johnathan's government are quick to point out that Nigeria's army has left hundreds dead in its fight against the militant group, many of whom were civilians. Economic factors are at play too: while Nigeria's economy may have been declared to be the biggest in Africa recently, living standards are still low, glaringly so when compared to those of the Nigerian political elite.

It may be tough for the Nigerian government to ignore international pressure. It's important to remember, however, that the stakes are far higher for those inside Nigeria. For example, when Lagos traders shut down some of the city's markets this week in protest, they were taking a financial hit. More worryingly, on Monday, Nigerian police arrested one leader of the protest, reportedly on the orders of the wife of President Jonathan. Slacktivism, this is not.

"The public scrutiny is embarrassing to the government and politicians and, as was the case in the arrest of leaders of the protest earlier this week, they want it to end," Soraya Chemaly, an activist who has been involved in the campaign in the United States, told me, adding that "any military operation to save the girls will be, given the history of those actions, very dangerous to the girls themselves."

There are also dangers that the message becomes too defuse as it spreads internationally. "It is important that the conversations about the abducted girls, the campaign to bring them back to safety [...] be done within a context," Egbunike explains. "It will be simplistic for instance to hinge what is happening in Nigeria as a Christian vs Muslim conflict, because it's more complicated than that."

Nor should it be forgotten that while this is an extreme example, it's a depressingly commonplace situation. "[The abducted girls] are not the first," Chemaly explains, "and will hardly be the last and if/when rescued the profound day-to-day issues regarding the lives of girls will recede once again from public view." As my colleague Ishaan Tharoor has pointed out, Joseph Kony's Lord's Resistance Army abducted 139 schoolgirls back in 1996.