Did Facebook's 400 million users make it inevitable that the long-lost Balzer sisters would find each other? Or was it a case of Stacy's hand reaching into the social media haystack and finding the needle that was Deb?

Perhaps their reunion simply was, as Deb described it, "the darnedest thing."

The Balzer sisters' story is among a couple of dozen collected in "Facebook Fairytales: Modern-Day Miracles to Inspire the Human Spirit" (Skyhorse, $12.95) by Emily Liebert. While Facebook's content is more associated with foiled job interviews and antics that should have stayed in Vegas, Liebert says that it's also an engine for good.

Last year, the site created a page called Facebook for Good, where members share stories of how they used the site as a tool in efforts that range from raising money for charities, to helping acquit the wrongfully accused, to finding lost cats.

Or lost sisters.

Deb Balzer, 48, lives in Minneapolis. But her story began in 1961, when she was born in Dunkirk, N.Y., near Buffalo. Two years later, sister Renee was born. Three years later, their parents divorced.

"During that era, divorce was a disgrace," said Balzer, especially so in a predominantly Catholic town. Several years later, their father left town and remarried.

When Balzer was 14, she tracked him down, only to learn that she and Renee had another sister named Stacy. But that marriage also had ended in divorce and the conversation stopped there. "Nobody said anything, so nobody ever said anything," she said, summing up the family dynamic. Yet she couldn't shake what she'd learned.

After their father's death in 1992, Balzer wrote to his second wife to tell her that she'd like to meet Stacy, but never got a reply. Seventeen years passed. Balzer moved to Minneapolis, where she works in public relations for the Animal Humane Society.

Early last year, she -- along with almost 2 million other people -- joined Facebook. Her 30-year high school reunion was approaching. Why not start catching up? Here's where the peculiar, circuitous power of social networking kicked in:

It turns out that Stacy also knew she had a long-lost sister and was trying to find her. In doing a Web search for Deb Balzer, she found that a woman with that name had posted a comment to someone named Rosalie on a Facebook page for a high school reunion. Yet she couldn't find Deb Balzer anywhere else on Facebook.

So Stacy sent a message to Rosalie -- they were total strangers -- explaining the situation and asking for help. "I've been trying to find her and my other sister Renee for many years, with no luck," she wrote. "You really have no idea what it would mean to me."

Rosalie -- who, as it happens, was an old friend of Deb Balzer's -- forwarded the message to Deb, and the circle was complete, the needle in the haystack found.

After that, things moved quickly. Deb told Renee that Stacy had been found and the sisters decided to rendezvous in Minneapolis over the July 4th holiday. Stacy flew in from Colorado, Renee from North Carolina. "I was worried, but it was all lovely," Balzer said.

The trio told their story pretty much to anyone and everyone they met over the weekend. "It was so obvious," she said. "We look like sisters, we all laugh crazily. I thought there would be a lot of tears, but we got on just as if we'd always been together. I think our father would have been really happy that his daughters finally got a chance to reconnect."

The sisters have decided to start a tradition of getting together every July 4th. "We know we'll never be able to make up for the Christmases, but this works because there's not a whole lot of emotional attachment to the day," Balzer said. "And we get fireworks!"

Kim Ode • 612-673-7185