From watching our neighbours to being watched at work, online and on the move, surveillance is everywhere. Information about every bit of our lives is valuable to somebody. Richard Bilton meets those who have made our private lives their business - ex-soldiers watching suspected workplace thieves, corporate spooks trawling companies' rubbish for lucrative secrets, suppliers in the booming trade in tracking devices, secret cameras and hidden microphones. He also delves into the criminal underworld of hackers and blaggers who steal and sell our information. Surveillance can benefit us all, helping make businesses more profitable and the services we use more convenient. But, as Richard discovers, surveillance has a darker side too.