For those interested in a more detailed account, Lewis' Flash Boys is a really great book. http://www.amazon.com/Flash-Boys-Michael-Lewis/dp/0393244660
I'm a Michael Lewis fan --- I even liked _Next: The Future Just Happened_ --- but this book was so disappointing I've actually become disillusioned. What else was he wrong about that I wasn't clued in enough to notice? Do Greek people in reality try hard to pay their taxes? Was Chad Bradford a terrible deal for the A's? Was Marillion a terrible band?