High frequency traders, high tech bandit or innovators? video~ http://news.bbc.co.uk/2/hi/business/10198133.stm High tech bandits or market innovators? It is the great debate surrounding so-called high frequency traders. These short-term, computer-centred firms have come under increased scrutiny in the US, as they have grown to dominate the industry. But high frequency traders themselves say they are vital to the markets, and long term investors should welcome them Caroline Hepker reports from New York.