About a month ago, while visiting my family in Oregon, I decided to browse my Nextdoor notifications. I don't log in every day and I'm not one of the many users who religiously comb the hyper-local social platform for neighborhood news. But if I get a particularly compelling update in my inbox, I'll click through. Some news about a thwarted break-in caught my eye, and then I saw it: a photo of a stranger sitting on my front porch. I checked the location of the poster; he lives in the same complex. "I found this person trying to break into the back unit," he wrote (my unit!?). The poster said the female stranger seemed confused, homeless, and maybe under the influence of something. She sat on the porch, insisted she lived there, and eventually left, but not before the Nextdoor poster could get a photo, which he uploaded through the app.

Earlier this week, a crime spree in San Francisco was thwarted thanks to Nextdoor and a Nest Cam.

It was disturbing to see an image of someone who tried to break into my house. It would have been less strange if someone had texted me the photo directly. Instead, I encountered it by chance on Nextdoor. But the social app is increasingly the medium of choice for neighborhood news, specifically coupled with images taken by would-be detectives, using consumer-first technologies to run homespun investigation rings.

Earlier this week, a one- to two-man crime spree in San Francisco was thwarted thanks to Nextdoor and the smart home product du jour, a Nest Cam. A wig-wearing thief was caught on camera trying to break into cars and homes—and thankfully apprehended, according to an ABC news affiliate. But what the report failed to mention was that the surveillance videos that helped police arrest the intruder were handed over to authorities by citizens using Nest Cam. The videos were originally posted to YouTube and Nextdoor.

In fact, the thief was a subject of much discussion on the platform. He was described by Nextdoor users as "the wig bandit," "the wig burglar," "glamorous," and "bowlegged", and there was a lot of conversation about whether the suspected perp was a man or a woman. (You'll only be able to click-through to that link if you live in this neighborhood—Nextdoor conversations for each locale are only accessible to residents in the immediate community.) There's some discussion about facial structure. Someone says maybe they should contact local salons with the evidence. It reads like a round table for a rather boring episode of Law & Order. But the cop talk isn't necessary much longer: Toward the end of the thread, the user who posted one of the videos says it's been given to the police. A short time later, the person was arrested.

https://www.youtube.com/watch?v=MEuHE5ekAQI&feature=youtu.be

Watching the Detectives

The Internet has gotten in trouble for armchair sleuthing before. After the Boston Massacre, Reddit tried its hand at finding the perpetrators, only to bring national attention to the wrong guy and temporarily thwart an actual criminal investigation. However, the Nextdoor community's relatively tactical approach to supplying local police with evidence and leads seems like it's, well, working. Various police and fire departments use the network to connect with residents. Nextdoor even has a way for public agencies specifically to use the site. (Nextdoor will help you craft a press release, should your agency choose to create an account.) Since launching the option, Nextdoor has partnered with more than 1,400 agencies, more than half of them being law enforcement.

All the threads wherein residents discussed the wig-wearing burglar weren't visible to the authorities.

A representative from Nextdoor says that authorities who choose to use the site are able to broadcast to neighborhoods using the network within their jurisdiction. They can post so people can see it, see responses to their posts, and exchange private messages with residents. But they can't access "any member content or conversations, as those are kept just within the neighborhoods themselves." So all the threads wherein residents discussed the wig-wearing burglar weren't visible to the authorities, and neither were threads about whatever else the users were talking about. And "whatever else" has a reputation for being bad.

Beginning soon after Nextdoor launched, users were criticizing the platform for giving voice to residents with subtle and not-so-subtle racist agendas. Racial profiling in particular, where residents post photos of "suspicious persons" in fits of unfounded, White Flight-era paranoia, has been observed. And less offensive but still a problem is the fact that Nextdoor is also a platform for neighborhood gossip, which can be nasty, inflammatory, exclusionary, or just dumb. Such is the case with every social network: For all the people using them in positive ways, there are those who use them negatively—and the negative voices tend to be louder, even when they're wrong. Being wrong about who had carpool last week is one thing, but it's entirely another when you're accusing someone of robbing you, sending police your Nest surveillance videos and connecting with them via Nextdoor. It's also a little uncomfortable to imagine your neighbors literally becoming Big Brother, recording your every move around the street, dissecting it later, possibly discussing it on Nextdoor.

New Safety Rules

But perhaps the trade-off is worth these risks: Sacramento is on a quest to become the safest big city in California, and after partnering with Nextdoor last year and using the site to monitor local incidents, crime fell 10 percent. It fell another 15 percent in 2014.

Beyond the wig thief, there are numerous examples of crimes being solved thanks to Nextdoor. A Phoenix community posted continuously about break-ins in the area, eventually leading police to arrest six people. Car break-ins in San Antonio ended in three arrests thanks to Nextdoor posts and footage posted there. In Nashville, a resident saw furniture stolen from a neighbor's yard, and posted it to Nextdoor along with a photo they shared with police. Three people were arrested. (I contacted four different police departments to ask how citizen's technology and Nextdoor have impacted their jobs and as of publishing, hadn't heard back from any of them.)

But overall, the stats are encouraging, and it's certainly a more positive use of Nextdoor than you usually hear. There's something a little strange about ordinary residents turning into DIY investigators and surveillance agencies, armed with Nextdoor accounts and webcams. But there's only so much a home security sticker on your front door is going to do. So should we all feel safer? Maybe a little—without Nextdoor and my neighbor's phone camera, I'd never know someone was trying to break into my apartment, or what she looked like. That said, there still isn't a new lock on my door.