It is Friday evening and Nicki Slawson's working week is at an end. Her job, as an executive with a charity in Kettering is rewarding though exhausting. It is the beginning of the weekend: the time when Mrs Slawson, 37, should be looking forward to some leisure time, perhaps at the cinema or in a restaurant. At 8pm she double-locks her front door and checks that the twin CCTV cameras bolted to the wall of her home are working. Mrs Slawson is not, as one might assume, locking the door behind her to go out for the evening, she is...