BBC iPlayer has quietly added a "shocking" new documentary that true crime fans have said is a "hard watch". As part of its Storyville documentary series, this time viewers are plunged into an undercover investigation as police target online crime against children. Titled Storyville: The Darkest Web, the documentary follows undercover investigators as they attempt to look into the hidden and darkest corners of the internet to stop those who exploit and cause harm to children and young people.