Neighbours in the US are using cameras that read car number plates to record vehicles driving down their streets. When there’s a crime they check through the footage and pass any leads on to the police. But critics say the Flock Safety system, run by a private company, is open to abuse and warn of privacy concerns. Is it too risky to encourage residents to do police work, or a realistic response to under-resourced law enforcement? Presenter: Tom Colls Producer: Claire Bates (Photo Credit: BBC)