When two of her husband’s work trucks were burgled in Georgia, Mary Chapman went to Facebook instead of the police. She messaged her friend who in turn forwarded it to another who thought she had seen something strange. Within a few hours, they had found the teenage suspect, confronted him and settled the problem by downgrading the charge after he apologized. The police hadn’t even come up with a name.

Others are also using the social network site for crimes. In the UK, a man started “Find the Sale RAPIST,” with images from a security video to help find a man who assaulted his girlfriend and has attracted 7,277 members. And a web designer who found a wallet was contacted by its owner through Facebook.