In the first of the new series, Aleks Krotoski explores how the web has influenced detection, from uncovering Osama Bin Laden to discovering the identity of long-abandoned Jane and John Does.

As human beings, what is it in our nature that drives us to find out the end of the story - even when that story has nothing to do with us?
The online world has made the detective mystery one in which we can all play a role. Hundreds of cold cases have been re-examined and re-explored by cyber sleuths around the world - and some cases have picked up definitive leads from eagle-eyed members of the public. But what are the implications for law enforcement, and how does detection work when so many of us are playing outside of the rules?

Producer: Victoria McArthur.