Facebook activism, the trendy process by which we do good by clicking often, was in its full glory last week after the death of Iranian student Neda Agha Soltan, killed by gunfire in the streets of Tehran. First, Neda showed up in Twitter feeds, then in Facebook status updates: 'is Neda,' some wrote after their own names. And when people started Facebook groups inspired by her death, we quickly joined them, feeling happy that we'd done something, that we'd contributed. But whether virtual virtuousness will result in real-world action is unpredictable, and has as much to do with human nature as it does with amassing enough numbers. This is the problem with activism born of social networking sites. The numbers are impressive. News outlets cited the groups, with names like 'Angel of Iran,' as examples of public outcry, potential signs of a turning point in the disputed Iranian elections. The largest of these groups, called simply 'Neda,' currently has nearly 36,000 members; dozens more had 1,000, or 100, or 10. Click click click. It was so simple to join. And ... now what? Was clicking an end unto itself? Do Facebook groups -- which are today often treated as the official barometer for a cause's importance; more members signifies more gravitas -- ever translate into significant change? 'I don't have a lot of time for rallies,' says Charles Hilton, of Baltimore. That's why he joined 'Neda,' founded by a Houston real estate agent named Ali Kohan. 'I haven't been keeping up with the news a lot lately, but ... from what I gather, there was no reason to target this woman.' What Hilton knew of her story touched him. So he clicked. It felt like a show of support his schedule could manage. Hilton illustrates what Mary Joyce calls 'the pluses and minuses for the low bar of entry' of Facebook groups. Joyce is the co-founder of DigiActive.org, an organization that helps grass-roots activists figure out how to use digital technology to boost their impact. The low bar of entry means that joining -- or starting -- a cause is easy, and that causes can reach and educate a wide range of people. That's the plus. But that ease also means that well-intentioned groups could balloon to thousands of members, most of whom lack activism experience. 'Commitment levels are opaque,' says Joyce, who last year took a leave from DigiActive to work as new-media operations manager for Barack Obama's campaign. 'Maybe a maximum of 5 percent are going to take action, and maybe it's closer to 1 percent. ... In most cases of Facebook groups, members do nothing. I haven't yet seen a case where the Facebook group has led to a sustained movement.' There have, of course, been big examples of single-event success: The Internet-based organization Burma Global Action Network began as one American's Facebook group, formed to support monks' protest. The group coordinated a global 'day of action' in 2007 that drew protesters around the world. More measurably, the release of Fouad Mourtada, imprisoned for impersonating a member of Moroccan royalty online, was attributed in part to protests that began on Facebook and Flickr and spread offline. But more often the stories of Facebook activism look like Egypt's April 6 Youth Movement earlier this year, in which a Facebook group calling for a national strike in support of laborers gained a much-publicized 75,000 Facebook members ... and then fizzled out in real life. In some ways, it's harder to cite the failures than the successes, because there are so many of them, disintegrating before they reach the public's eye. 'Click-through activism' is the term used by Chris Csikszentmih lyi, the co-director of MIT's Center for Future Civic Media to describe the participants who might excitedly flit into an online group and then flutter away to something else. In some ways, he says, the ease of the medium 'reminds me of dispensations the Catholic Church used to give.' A better scenario for Internet activism, Csikszentmih lyi says, would be if causes could break down their needs into discrete tasks, and then farm those tasks out to qualified and willing individuals connected by the power of the Internet. But plain old Facebook groups? Attention shifts quickly online. It's still too soon to tell what tangible change the thousands of virtual Neda supporters will effect. Some groups were founded as simply virtual memorials, with no plans for future action, and those groups have already fulfilled their duty. 'Neda' is still drawing new members, though not as quickly as last week. Kohan, the founder, says that he hopes the group will turn into a foundation, and he's seeking donations from universities. Founders of other Neda groups, including the 4,000-member 'Never Forget Neda,' say they never expected their groups to grow so large, and are now considering how -- and whether -- to leverage the numbers further. But what if members don't want to be leveraged? What if they just want to join? As Anders Colding-Jorgensen, a psychologist and lecturer on social media at the University of Copenhagen, says, 'Just like we need stuff to furnish our homes to show who we are, on Facebook we need cultural objects that put together a version of me that I would like to present to the public.' 