For transplant centers, these occasional, often social media-driven spikes of interest can be difficult.

A year and a half ago, transplant surgeon Talia Baker, who specializes in living donors, found herself with an unlikely problem: She had too many people offering up their organs.

Baker was taking care of a baby, only a few months old, with just days to live. When it turned out that neither parent was a match for the organ the child so desperately needed, the baby's social media-savvy mother posted an entreaty on Facebook, alone with the donor hotline number for Baker's transplant center. Her post, which Baker calls "heart-wrenching," spread rapidly, and within 24 hours, they'd received more than 100 offers to donate.

"We work in feast and famine," Baker says of her profession. "Sometimes there'll be a ton of organs and we're up for a week. ... And then we'll have two weeks where we do nothing." But even compared with feast times, the generosity inspired by this child would have been remarkable, a clear product of the deeply felt connections that strangers can form on social media.

For transplant centers, these occasional, often social media-driven spikes of interest can be difficult, partly because they're rarely set up to screen dozens of calls that can come in when a story finds wider notice. With the clock ticking, Baker had little time to cull through the list in search of an ideal candidate. Meanwhile, professional ethics further complicated the timetable: She had to take time out of her own schedule to explain to each of the potential volunteers what they'd be getting into, ensuring that they understood it was a major surgery-one that could put them at risk.

After carefully triaging her list, Baker found an appropriate fit, one that would ultimately save the baby's life. Along the way, though, she learned that many of the other volunteers might still be willing to donate even if they couldn't give to the charismatic patient who'd caught their attention.

Thinking it might be possible to leverage those reserves of generosity, Baker reached out to Jenna Arnold and Greg Segal, co-founders of a nonprofit called Organize that aspires to bring the organ donation process up-to-date for the social media age. As I wrote last year, Arnold and her collaborators had learned that a tweet or Facebook post about your desire to donate your organs after death might be enough to register you. At the time, they set out to make it easier for state organ registries to access that information-and to make it easier for family members to process the deceased's wishes as a difficult time. Living organ donation, however, was a different and less ...