My neighborhood is experiencing a crime wave. Just on my block in the last week, several packages were stolen from doorsteps and tires have been slashed on at least two cars. I found all of this out from an app that's quickly becoming our neighborhood's best security system. "I heard it from Fred two doors down" is being replaced by "I saw it on Nextdoor."
Nextdoor is a location-based social network meant to connect neighbors. By signing up and giving your address, you're placed in a "neighborhood" of users who live in your immediate vicinity. Its intended uses, according to a promotional video, are to borrow a ladder or find a babysitter. In my neighborhood, probably more than half of the Nextdoor posts are about crime.