This time last year a video featuring Hillary Clinton rapidly ascended to the top spot in YouTube's daily rankings. The slickly produced video was a parody of an Apple advertisement based on George Orwell's "Big Brother" from 1984 . It was Mrs Clinton who was depicted as Big Brother. Again and again it replayed a clip culled from her own campaign website in which she said: "Let the conversation begin".

Peter Leyden, a former -editor of Wired and now director of the New Politics Institute, which examines how technology affects US campaigns, says the Big Brother video perfectly encapsulated the difference between Barack Obama's campaign and that of Mrs Clinton.