We were at school together http://pornhub.in.net/ porn.hub  The shutdown was another sign that the days of stock brokers in colorful jackets roaming the floor of the stock exchange have faded away. Now powerful computer programs dominate trading by sifting through reams of data and executing trades in fractions of a second. That makes trading faster and, arguably, more efficient. But it also introduces more possibilities for errors that can jolt the entire market.