By Mauro Whiteman
SAN FRANCISCO (Reuters) - Social networks often get accused of fostering crime by letting others know when people are not home, but Nextdoor.com is being used to bust burglars.
While community-based social network Nextdoor didn't set out to catch thieves, the 9-month old San Francisco startup is increasingly helping in the apprehension of criminals or in crime prevention, users say.
And Silicon Valley venture firms are beginning to notice. On Tuesday, Nextdoor said it raised $18.6 million from Benchmark Capital, DAG Ventures, Greylock Partners and Shasta Ventures, valuing the company at more than $100 million.
Nextdoor's co-founder and Chief Executive Nirav Tolia told Reuters the company has signed up more than 3,700 neighborhoods nationwide, and is looking to expand its network.
The startup began as a way for locals to connect and the crime-fighting aspect evolved from that, according to Tolia.
"What happened when we connected neighbors is something that we couldn't predict: neighbors looking out for each other," Tolia said. "Connected neighbors equal safer neighborhoods."
Residents of a neighborhood can sign up for free for the service, which allows the members to exchange information, recommendations and discuss topics of interest. Crime and safety make up a fifth of Nextdoor posts, according to the company.
"We wanted to return America to that place where we can rely on our neighbors," Tolia said.
One feature that has taken off is "Urgent Alerts," which Nextdoor members can use to send out alerts -- distributed by text message -- to neighbors on suspicious activity.
Becki, a mother and a member of an Oakland Nextdoor network who would not give her full name for security reasons, said she and her neighbors used the social network to warn each other of two suspicious teenagers who were going door to door, saying they were selling magazine subscriptions for charity.
Posts on Nextdoor about the two pointed out discrepancies in responses about what college they attended and what charity they were raising funds for. By the time the teens arrived at Becki's doorstep -- about three minutes after the first alert -- she was prepared to collect descriptions for the police.
The teens were later arrested and tied to a robbery that had happened days earlier -- also reported on Nextdoor.
"It allows us to give information to each other in real time," she said. "It lets you act quickly ... rather than after the fact when you can't really do anything."
In areas experiencing rising criminal activity, Nextdoor has become a welcome tool. Bob Thornburg, a 63-year-old electrical contractor from Santa Fe, New Mexico, founded the Sol y Lomas neighborhood network on Nextdoor specifically to ward off crime.
"That's actually what got us started here," he said. Prior to Nextdoor, he had run an email group to "spread the word if something happened. The whole thing was about crime because we were having a bit of a crime wave."
Kenneth Denson had used Yahoo Groups as a way to post about community issues until February, when he started a Nextdoor network in Dallas.
"This would be another really useful tool in Dallas's toolbox," said Denson, who is in early discussions with members of the Dallas City Council to expand the network citywide.
The City Program, which has existed since Nextdoor launched, works alongside city leaders to roll out networks across all neighborhoods. The city gets its own page, and a system for pushing out posts to neighborhoods in its jurisdiction.
More than 60 municipalities now work with Nextdoor, and 41 have the City Program in effect. Lafayette, Colorado, joined in May and Mayor Pro Tem Steve Kracha said the program could augment existing systems that haven't adapted to new technology.
"The Reverse-911 system works fine if you're in your house," Kracha said. But with many neighbors ditching traditional landlines in favor of smartphones, a text or email alert can be more effective in disseminating information quickly, he said.
In Goleta, California, crime prevention makes up about 35 percent of the city's official posts, said Valerie Kushnerov, Goleta's public information officer.
"I often joke that soon we'll have signs saying, 'This neighborhood is protected by Nextdoor,'" she said.
(Reporting By Mauro Whiteman; Editing by Kenneth Barry)