Paedophile Hunters: Rise of the Vigilantes

In this hard-hitting documentary, journalist, Livvy Haydock, investigates the rise of certain groups targeting suspected paedophiles and attempting to bring them to justice.  With no legal powers or support from the authorities, are these groups helping or hindering the police?

By taking the law into their own hands, are they capturing predators who would otherwise slip through the net, or making a vital conviction more difficult with their methods?