Safety Twitter

To some degree, crime is a communication problem. Crime used to happen mostly in the gloom of night, or otherwise when no one was looking. See, responsible social people dislike it when people are victimized, and have formed organizations that punish offenders. In modern times, this is the police and courts. Police halt offenders in their tracks, and turn them over to the court system for punishment. So to successfully commit a crime, one must keep the police unaware of it.
So Discovery news reports that a think-tank imagines a Twitter-like interface (possibly even twitter itself), in which people can anonymously report the locations of crimes, which will rapidly attract police attention. If enough people keep this up, crime will effectively be impossible. Fairies dance and unicorns sing in Utopia.
Of course, a big rub that Discovery points out is that humans are not cyborgs that can magically connect to the internet. Crime is most common in neighborhoods where people can't afford expensive electronics, and the obvious answer of public terminals attracts vandalism. (There are some people out there who just love to ruin things for other people, even if they get no direct benefit from doing something like that. Give a street a public terminal and inevitably someone will doodle on it, someone else will pee on it, and someone will use it to look up porn, even if 95% of the other people use it responsibly.)
Another approach has been the UK's plastering of ubiquitous cameras. From what British people have told me, that did not work. People resented the cameras, especially because the government took an obnoxiously paternal approach to objections. (Namely, "It's for your own good, now STFU.") Crime did not noticeably reduce, as the local thugs took to wearing face-obscuring garments like hoods, and the cameras got endlessly vandalized by angry citizens.